Metha  Meetam, Keren, Nir , Ohad, Itzhak , and Pakrasi, Himadri B. 1999. ?The Psby Protein Is Not Essential For Oxygenic Photosynthesis In The Cyanobacterium Synechocystis Sp. Pcc 6803?. Plant Physiology, 121, 4, Pp. 1267?1272.