text: * [http://www.eanet.asia/ Acid Deposition Monitoring Program in East Asia (EANET)]
  * [https://www.canada.ca/en/environment-climate-change/services/air-pollution/monitoring-networks-data/canadian-air-precipitation.html Canadian Air and Precipitation Monitoring Network (CAPMoN)]
  * [https://www.epa.gov/castnet Clean Air Status and Trends Network (CASTNET)]
  * [https://www.epa.gov/great-lakes-monitoring Great Lakes National Program Office (GLNPO)]
  * [http://apmmn.org/About/ Asia-Pacific Mercury Monitoring Network (APMMN)]