OLRIK, Kirsten. The occurrence of planktonic desmid species in Danish lakes and ponds related to total nitrogen and phosphorus contents of the water body. In Biologia. Section A. Section B. Section C, Botany. Zoology. Cellular and molecular biology. ISSN 0006-3088. ISSN 1335-6372. ISSN 1335-6380. ISSN 1335-6399. Bratislava : Slovak Academic Press, 2003, vol. 58, no. 4, s. 709-716.