Não informado. (1988). Nordic Journal of Freshwater Research. Institute of Freshwater Research.
Chicago-referens (17:e uppl.)Não informado. Nordic Journal of Freshwater Research. Drottningholm, Suecia: Institute of Freshwater Research, 1988.
MLA-referens (8:e uppl.)Não informado. Nordic Journal of Freshwater Research. Institute of Freshwater Research, 1988.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.