Palter, J., S. León Coto, and D. Ballestero. “The Distribution of Nutrients, Dissolved Oxygen and Chlorophyll a in the Upper Gulf of Nicoya, Costa Rica, a Tropical Estuary”. Revista De Biología Tropical, vol. 55, no. 2, June 2007, pp. 427–436, doi:10.15517/rbt.v55i2.6022.