China Diagnostic tympanometer Market Research Report 2018

March 2018 | 97 pages | ID: CEFFECE076DQEN
QYResearch

Abstracts

The global Diagnostic tympanometer market is valued at XX million USD in 2017 and is expected to reach XX million USD by the end of 2025, growing at a CAGR of XX% between 2017 and 2025.

China plays an important role in global market, with market size of xx million USD in 2017 and will be xx million USD in 2025, with a CAGR of xx%.

This report studies the Diagnostic tympanometer development status and future trend in China, focuses on top players in China, also splits Diagnostic tympanometer by type and by applications, to fully and deeply research and reveal the market general situation and future forecast.

The major players in China market include

• Interacoustics
• Inventis
• Otometrics
• PATH medical
• Welch Allyn
• Grason Stadler
• Maico
• Oscilla
• Braun International
• Audiology Systems

Geographically, this report splits the China market into six regions,

• South China
• East China
• Southwest China
• Northeast China
• North China
• Central China
• Northwest China

On the basis of product, this report displays the sales volume (K Units), revenue (Million USD), product price (USD/Unit), market share and growth rate of each type, primarily split into

• Handheld type
• Table type

On the basis of the end users/application, this report covers

• Hospital
• Clinics
• Others

If you have any special requirements, please let us know and we will offer you the report as you want.

Contents

China Diagnostic tympanometer Market Research Report 2018

1 DIAGNOSTIC TYMPANOMETER OVERVIEW

1.1 Product Overview and Scope of Diagnostic tympanometer
1.2 Classification of Diagnostic tympanometer by Product Category
  1.2.1 China Diagnostic tympanometer Sales (K Units) Comparison by Type (2013-2025)
  1.2.2 China Diagnostic tympanometer Sales (K Units) Market Share by Type in 2017
  1.2.3 Handheld type
  1.2.4 Table type
1.3 China Diagnostic tympanometer Market by Application/End Users
  1.3.1 China Diagnostic tympanometer Sales (K Units) and Market Share Comparison by Applications (2013-2025)
  1.3.2 Hospital
  1.3.3 Clinics
  1.3.4 Others
1.4 China Diagnostic tympanometer Market by Region
  1.4.1 China Diagnostic tympanometer Market Size (Million USD) Comparison by Region (2013-2025)
  1.4.2 South China Diagnostic tympanometer Status and Prospect (2013-2025)
  1.4.3 East China Diagnostic tympanometer Status and Prospect (2013-2025)
  1.4.4 Southwest China Diagnostic tympanometer Status and Prospect (2013-2025)
  1.4.5 Northeast China Diagnostic tympanometer Status and Prospect (2013-2025)
  1.4.6 North China Diagnostic tympanometer Status and Prospect (2013-2025)
  1.4.7 Central China Diagnostic tympanometer Status and Prospect (2013-2025)
1.5 China Market Size (Sales and Revenue) of Diagnostic tympanometer (2013-2025)
  1.5.1 China Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2025)
  1.5.2 China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (%)(2013-2025)

2 CHINA DIAGNOSTIC TYMPANOMETER MARKET COMPETITION BY PLAYERS/MANUFACTURERS

2.1 China Diagnostic tympanometer Sales and Market Share of Key Players/Manufacturers (2013-2018)
2.2 China Diagnostic tympanometer Revenue and Share by Players/Manufacturers (2013-2018)
2.3 China Diagnostic tympanometer Average Price (USD/Unit) by Players/Manufacturers (2013-2018)
2.4 China Diagnostic tympanometer Market Competitive Situation and Trends
  2.4.1 China Diagnostic tympanometer Market Concentration Rate
  2.4.2 China Diagnostic tympanometer Market Share of Top 3 and Top 5 Players/Manufacturers
  2.4.3 Mergers & Acquisitions, Expansion in China Market
2.5 China Players/Manufacturers Diagnostic tympanometer Manufacturing Base Distribution, Sales Area, Product Types

3 CHINA DIAGNOSTIC TYMPANOMETER SALES AND REVENUE BY REGION (2013-2018)

3.1 China Diagnostic tympanometer Sales (K Units) and Market Share by Region (2013-2018)
3.2 China Diagnostic tympanometer Revenue (Million USD) and Market Share by Region (2013-2018)
3.3 China Diagnostic tympanometer Price (USD/Unit) by Regions (2013-2018)

4 CHINA DIAGNOSTIC TYMPANOMETER SALES AND REVENUE BY TYPE/ PRODUCT CATEGORY (2013-2018)

4.1 China Diagnostic tympanometer Sales (K Units) and Market Share by Type/ Product Category (2013-2018)
4.2 China Diagnostic tympanometer Revenue (Million USD) and Market Share by Type (2013-2018)
4.3 China Diagnostic tympanometer Price (USD/Unit) by Type (2013-2018)
4.4 China Diagnostic tympanometer Sales Growth Rate (%) by Type (2013-2018)

5 CHINA DIAGNOSTIC TYMPANOMETER SALES BY APPLICATION (2013-2018)

5.1 China Diagnostic tympanometer Sales (K Units) and Market Share by Application (2013-2018)
5.2 China Diagnostic tympanometer Sales Growth Rate (%) by Application (2013-2018)
5.3 Market Drivers and Opportunities

6 CHINA DIAGNOSTIC TYMPANOMETER PLAYERS/SUPPLIERS PROFILES AND SALES DATA

6.1 Interacoustics
  6.1.1 Company Basic Information, Manufacturing Base and Competitors
  6.1.2 Diagnostic tympanometer Product Category, Application and Specification
    6.1.2.1 Product A
    6.1.2.2 Product B
  6.1.3 Interacoustics Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.1.4 Main Business/Business Overview
6.2 Inventis
  6.2.1 Company Basic Information, Manufacturing Base and Competitors
  6.2.2 Diagnostic tympanometer Product Category, Application and Specification
    6.2.2.1 Product A
    6.2.2.2 Product B
  6.2.3 Inventis Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.2.4 Main Business/Business Overview
6.3 Otometrics
  6.3.1 Company Basic Information, Manufacturing Base and Competitors
  6.3.2 Diagnostic tympanometer Product Category, Application and Specification
    6.3.2.1 Product A
    6.3.2.2 Product B
  6.3.3 Otometrics Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.3.4 Main Business/Business Overview
6.4 PATH medical
  6.4.1 Company Basic Information, Manufacturing Base and Competitors
  6.4.2 Diagnostic tympanometer Product Category, Application and Specification
    6.4.2.1 Product A
    6.4.2.2 Product B
  6.4.3 PATH medical Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.4.4 Main Business/Business Overview
6.5 Welch Allyn
  6.5.1 Company Basic Information, Manufacturing Base and Competitors
  6.5.2 Diagnostic tympanometer Product Category, Application and Specification
    6.5.2.1 Product A
    6.5.2.2 Product B
  6.5.3 Welch Allyn Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.5.4 Main Business/Business Overview
6.6 Grason Stadler
  6.6.1 Company Basic Information, Manufacturing Base and Competitors
  6.6.2 Diagnostic tympanometer Product Category, Application and Specification
    6.6.2.1 Product A
    6.6.2.2 Product B
  6.6.3 Grason Stadler Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.6.4 Main Business/Business Overview
6.7 Maico
  6.7.1 Company Basic Information, Manufacturing Base and Competitors
  6.7.2 Diagnostic tympanometer Product Category, Application and Specification
    6.7.2.1 Product A
    6.7.2.2 Product B
  6.7.3 Maico Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.7.4 Main Business/Business Overview
6.8 Oscilla
  6.8.1 Company Basic Information, Manufacturing Base and Competitors
  6.8.2 Diagnostic tympanometer Product Category, Application and Specification
    6.8.2.1 Product A
    6.8.2.2 Product B
  6.8.3 Oscilla Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.8.4 Main Business/Business Overview
6.9 Braun International
  6.9.1 Company Basic Information, Manufacturing Base and Competitors
  6.9.2 Diagnostic tympanometer Product Category, Application and Specification
    6.9.2.1 Product A
    6.9.2.2 Product B
  6.9.3 Braun International Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.9.4 Main Business/Business Overview
6.10 Audiology Systems
  6.10.1 Company Basic Information, Manufacturing Base and Competitors
  6.10.2 Diagnostic tympanometer Product Category, Application and Specification
    6.10.2.1 Product A
    6.10.2.2 Product B
  6.10.3 Audiology Systems Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
  6.10.4 Main Business/Business Overview

7 DIAGNOSTIC TYMPANOMETER MANUFACTURING COST ANALYSIS

7.1 Diagnostic tympanometer Key Raw Materials Analysis
  7.1.1 Key Raw Materials
  7.1.2 Price Trend of Key Raw Materials
  7.1.3 Key Suppliers of Raw Materials
  7.1.4 Market Concentration Rate of Raw Materials
7.2 Proportion of Manufacturing Cost Structure
  7.2.1 Raw Materials
  7.2.2 Labor Cost
  7.2.3 Manufacturing Expenses
7.3 Manufacturing Process Analysis of Diagnostic tympanometer

8 INDUSTRIAL CHAIN, SOURCING STRATEGY AND DOWNSTREAM BUYERS

8.1 Diagnostic tympanometer Industrial Chain Analysis
8.2 Upstream Raw Materials Sourcing
8.3 Raw Materials Sources of Diagnostic tympanometer Major Manufacturers in 2017
8.4 Downstream Buyers

9 MARKETING STRATEGY ANALYSIS, DISTRIBUTORS/TRADERS

9.1 Marketing Channel
  9.1.1 Direct Marketing
  9.1.2 Indirect Marketing
  9.1.3 Marketing Channel Development Trend
9.2 Market Positioning
  9.2.1 Pricing Strategy
  9.2.2 Brand Strategy
  9.2.3 Target Client
9.3 Distributors/Traders List

10 MARKET EFFECT FACTORS ANALYSIS

10.1 Technology Progress/Risk
  10.1.1 Substitutes Threat
  10.1.2 Technology Progress in Related Industry
10.2 Consumer Needs/Customer Preference Change
10.3 Economic/Political Environmental Change

11 CHINA DIAGNOSTIC TYMPANOMETER MARKET SIZE (SALES AND REVENUE) FORECAST (2018-2025)

11.1 China Diagnostic tympanometer Sales (K Units), Revenue (Million USD) Forecast (2018-2025)
11.2 China Diagnostic tympanometer Sales (K Units) Forecast by Type (2018-2025)
11.3 China Diagnostic tympanometer Sales (K Units) Forecast by Application (2018-2025)
11.4 China Diagnostic tympanometer Sales (K Units) Forecast by Region (2018-2025)

12 RESEARCH FINDINGS AND CONCLUSION

13 METHODOLOGY AND DATA SOURCE

13.1 Methodology/Research Approach
  13.1.1 Research Programs/Design
  13.1.2 Market Size Estimation
  13.1.3 Market Breakdown and Data Triangulation
13.2 Data Source
  13.2.1 Secondary Sources
  13.2.2 Primary Sources
13.3 Disclaimer
13.4 Author List

The report requires updating with new data and is sent in 2-3 business days after order is placed.

List Of Tables

LIST OF TABLES AND FIGURES

Figure Global and China Market Size (Million USD) Comparison (2013-2025)
Table Diagnostic tympanometer Sales (K Units) and Revenue (Million USD) Market Split by Product Type
Table Diagnostic tympanometer Sales (K Units) by Application (2013-2025)
Figure Product Picture of Diagnostic tympanometer
Table China Diagnostic tympanometer Sales (K Units) and Growth Rate (%) Comparison by Types (Product Category) (2013-2025)
Figure China Diagnostic tympanometer Sales Volume Market Share by Types in 2017
Figure Handheld type Product Picture
Figure Table type Product Picture
Figure China Diagnostic tympanometer Sales (K Units) Comparison by Application (2013-2025)
Figure China Sales Market Share (%) of Diagnostic tympanometer by Application in 2017
Figure Hospital Examples
Table Key Downstream Customer in Hospital
Figure Clinics Examples
Table Key Downstream Customer in Clinics
Figure Others Examples
Table Key Downstream Customer in Others
Figure South China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure East China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure Southwest China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure Northeast China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure North China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure Central China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (2013-2025)
Figure China Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2025)
Figure China Diagnostic tympanometer Revenue (Million USD) and Growth Rate (%)(2013-2025)
Table China Diagnostic tympanometer Sales of Key Players/Manufacturers (2013-2018)
Table China Diagnostic tympanometer Sales Share (%) by Players/Manufacturers (2013-2018)
Figure 2017 China Diagnostic tympanometer Sales Share (%) by Players/Manufacturers
Figure 2017 China Diagnostic tympanometer Sales Share (%) by Players/Manufacturers
Table China Diagnostic tympanometer Revenue by Players/Manufacturers (2013-2018)
Table China Diagnostic tympanometer Revenue Market Share (%) by Players/Manufacturers (2013-2018)
Figure 2017 China Diagnostic tympanometer Revenue Market Share (%) by Players/Manufacturers
Figure 2017 China Diagnostic tympanometer Revenue Market Share (%) by Players/Manufacturers
Table China Market Diagnostic tympanometer Average Price of Key Players/Manufacturers (2013-2018)
Figure China Market Diagnostic tympanometer Average Price of Key Players/Manufacturers in 2017
Figure China Diagnostic tympanometer Market Share of Top 3 Players/Manufacturers
Figure China Diagnostic tympanometer Market Share of Top 5 Players/Manufacturers
Table China Players/Manufacturers Diagnostic tympanometer Manufacturing Base Distribution and Sales Area
Table China Players/Manufacturers Diagnostic tympanometer Product Category
Table China Diagnostic tympanometer Sales (K Units) by Regions (2013-2018)
Table China Diagnostic tympanometer Sales Share (%) by Regions (2013-2018)
Figure China Diagnostic tympanometer Sales Share (%) by Regions (2013-2018)
Figure China Diagnostic tympanometer Sales Market Share (%) by Regions in 2017
Table China Diagnostic tympanometer Revenue (Million USD) and Market Share by Regions (2013-2018)
Table China Diagnostic tympanometer Revenue Market Share (%) by Regions (2013-2018)
Figure China Diagnostic tympanometer Revenue Market Share (%) by Regions (2013-2018)
Figure China Diagnostic tympanometer Revenue Market Share (%) by Regions in 2017
Table China Diagnostic tympanometer Price (USD/Unit) by Regions (2013-2018)
Table China Diagnostic tympanometer Sales (K Units) by Type (2013-2018)
Table China Diagnostic tympanometer Sales Share (%) by Type (2013-2018)
Figure China Diagnostic tympanometer Sales Share (%) by Type (2013-2018)
Figure China Diagnostic tympanometer Sales Market Share (%) by Type in 2017
Table China Diagnostic tympanometer Revenue (Million USD) and Market Share by Type (2013-2018)
Table China Diagnostic tympanometer Revenue Market Share (%) by Type (2013-2018)
Figure Revenue Market Share of Diagnostic tympanometer by Type (2013-2018)
Figure Revenue Market Share of Diagnostic tympanometer by Type in 2017
Table China Diagnostic tympanometer Price (USD/Unit) by Types (2013-2018)
Figure China Diagnostic tympanometer Sales Growth Rate (%) by Type (2013-2018)
Table China Diagnostic tympanometer Sales (K Units) by Applications (2013-2018)
Table China Diagnostic tympanometer Sales Market Share (%) by Applications (2013-2018)
Figure China Diagnostic tympanometer Sales Market Share (%) by Application (2013-2018)
Figure China Diagnostic tympanometer Sales Market Share (%) by Application in 2017
Table China Diagnostic tympanometer Sales Growth Rate (%) by Application (2013-2018)
Figure China Diagnostic tympanometer Sales Growth Rate (%) by Application (2013-2018)
Table Interacoustics Diagnostic tympanometer Basic Information List
Table Interacoustics Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Interacoustics Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Interacoustics Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Interacoustics Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Inventis Diagnostic tympanometer Basic Information List
Table Inventis Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Inventis Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Inventis Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Inventis Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Otometrics Diagnostic tympanometer Basic Information List
Table Otometrics Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Otometrics Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Otometrics Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Otometrics Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table PATH medical Diagnostic tympanometer Basic Information List
Table PATH medical Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure PATH medical Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure PATH medical Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure PATH medical Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Welch Allyn Diagnostic tympanometer Basic Information List
Table Welch Allyn Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Welch Allyn Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Welch Allyn Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Welch Allyn Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Grason Stadler Diagnostic tympanometer Basic Information List
Table Grason Stadler Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Grason Stadler Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Grason Stadler Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Grason Stadler Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Maico Diagnostic tympanometer Basic Information List
Table Maico Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Maico Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Maico Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Maico Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Oscilla Diagnostic tympanometer Basic Information List
Table Oscilla Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Oscilla Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Oscilla Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Oscilla Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Braun International Diagnostic tympanometer Basic Information List
Table Braun International Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Braun International Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Braun International Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Braun International Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Audiology Systems Diagnostic tympanometer Basic Information List
Table Audiology Systems Diagnostic tympanometer Sales (K Units), Revenue (Million USD), Price (USD/Unit) and Gross Margin (%)(2013-2018)
Figure Audiology Systems Diagnostic tympanometer Sales (K Units) and Growth Rate (%)(2013-2018)
Figure Audiology Systems Diagnostic tympanometer Sales Market Share (%) in China (2013-2018)
Figure Audiology Systems Diagnostic tympanometer Revenue Market Share (%) in China (2013-2018)
Table Production Base and Market Concentration Rate of Raw Material
Figure Price Trend of Key Raw Materials
Table Key Suppliers of Raw Materials
Figure Manufacturing Cost Structure of Diagnostic tympanometer
Figure Manufacturing Process Analysis of Diagnostic tympanometer
Figure Diagnostic tympanometer Industrial Chain Analysis
Table Raw Materials Sources of Diagnostic tympanometer Major Players/Manufacturers in 2017
Table Major Buyers of Diagnostic tympanometer
Table Distributors/Traders List
Figure China Diagnostic tympanometer Sales (K Units) and Growth Rate (%) Forecast (2018-2025)
Figure China Diagnostic tympanometer Revenue (Million USD) and Growth Rate Forecast (2018-2025)
Figure China Diagnostic tympanometer Price (USD/Unit) Trend Forecast (2018-2025)
Table China Diagnostic tympanometer Sales (K Units) Forecast by Type (2018-2025)
Figure China Diagnostic tympanometer Sales (K Units) Forecast by Type (2018-2025)
Figure China Diagnostic tympanometer Sales Volume Market Share Forecast by Type in 2025
Table China Diagnostic tympanometer Sales (K Units) Forecast by Application (2018-2025)
Figure China Diagnostic tympanometer Sales Volume Market Share Forecast by Application (2018-2025)
Figure China Diagnostic tympanometer Sales Volume Market Share Forecast by Application in 2025
Table China Diagnostic tympanometer Sales (K Units) Forecast by Regions (2018-2025)
Table China Diagnostic tympanometer Sales Volume Share Forecast by Regions (2018-2025)
Figure China Diagnostic tympanometer Sales Volume Share Forecast by Regions (2018-2025)
Figure China Diagnostic tympanometer Sales Volume Share Forecast by Regions in 2025
Table Research Programs/Design for This Report
Figure Bottom-up and Top-down Approaches for This Report
Figure Data Triangulation
Table Key Data Information from Secondary Sources
Table Key Data Information from Primary Sources