First report of microcystins in the tropical cyanobacteria Microcystis panniformis Komarek et al isolated from Brazil - Pinto, Ernani; Kujbida, P.; Cardozo, K. H. M.; Moura, A. N.; Colepicolo, Pio; Bittencourt-Oliveira, Maria do Carmo (International Conference on Harmful Algal Blooms, 2004)