@article{Kondratyeva_2002 author = {N. V. Kondratyeva and O. A. Kislova}, title = {Variability of life cycles of Nostoc Vauch. (Cyanophyta) and problems of systematics}, journal = {International Journal on Algae}, issn = {1521-9429}, year = {2002}, volume = {4}, number = {2}, pages = {72--85} }