6De P K. The role of blue - green algae in nitrogen fixation in rice - field[J]. Proc Roy Soc London, 1939,127:121 - 139.
7Okay O S, Morkoc E. Effects of two herbicidal wastewaters on Chlorella sp. and phaeodactylum tricornutum[J]. Environ Pollut, 1994,84:1 - 6.
8Yan Guoan, Yu Jinyi. Comparison of the effects of nitrogen on removal, growth and some physiological characteristics of immobilized and free Chlorells Vulgaris: Ⅰ Growth and nutrient removal[J]. Toxicological and Environmental Chemistry, 1997,58:63 - 74.