Vakili, Fereshte, Ghorchibeigi, Kayvan, Soltani, Neda, Shokravi, Shadman (2006) ‘The effect of continuous illumination and photoperiods on growth and heterocyst frequency of cyanobacterium Fischerella ambigua
 from Golestan province’, Journal of Plant Environmental Physiology, 1(2), pp. 11-20. doi:10.30495/iper.2006.690227