Preciado, Olegario, et al. “Characterization of Traditional Productive System With Cocoa Tree (Theobroma Cacao L.) in Tumaco, Nariño”. Revista De Ciencias Agrícolas, vol. 28, no. 2, July 2011, pp. 58-69, https://revistas.udenar.edu.co/index.php/rfacia/article/view/15.