Gocke, Klaus, William Bussing, and Jorge Cortés. 1990. “The Annual Cycle of Primary Productivity in Laguna De Río Cuarto, a Volcanic Lake (maar) in Costa Rica”. Revista De Biología Tropical 38 (2B):387–394. https://revistas.ucr.ac.cr/index.php/rbt/article/view/25432.