1. Antarctic Freshwater Diatoms. http://huey.colorado.edu/diatoms
2. Canadian Diatom Database. http://open.canada.ca/en/ckan/canadian-diatom-database
3. COPDESS (2015) Statement of commitment from earth and space science publishers and data facilities. [cited August 25, 2015]. http://www.copdess.org/statement-of-commitment/
4. Diatom Paleolimnology Data Cooperative. http://diatom.acnatsci.org/dpdc
5. Diatoms of the United States. http://westerndiatoms.colorado.edu