Pérez, A. “Nitrogenous Fertilization of Coffea Canephora Pierre Var. Robusta Related to Yield, and Some Chemical and Microbiological Indicators of Cambisols in Cuba”. Cultivos Tropicales, vol. 31, no. 3, July 2012, pp. 66-74, https://ediciones.inca.edu.cu/index.php/ediciones/article/view/111.