NYGAARD, Gunnar 1950 ('1949' p.b. 10.i.1950) Hydrobiological studies on some Danish ponds and lakes. Part II: the quotient hypothesis and some new or little known phytoplankton organisms K. Danske Vid. Selsk. Biol. Skr. 7{1}. 293 pp., 126 figs., IV tables in text and on Beilagen 86 |