Isolation and identification of a new antibacterial entity from the Antarctic cyanobacterium Nostoc CCC 537 - Asthana, Ravi K.; Deepali; Tripathi, Manoj K.; Srivastava, Arunima; Singh, Akhilesh P.; Singh, Sureshwar P.; Nath, Gopal; Srivastava, Ranjana; Srivastava, Brahm S. (Journal of Applied Phycology, 2008)