Cepeda Arias, Édisson Ramiro, and José Salvador Montañez Pérez. “Analysis of Alternatives for the Use or Final Disposal of the Sludge Generated at the Paipa (Boyacá) Mini-Wastewater Treatment Plant”. Revista Facultad De Ingeniería, vol. 16, no. 22, June 2009, pp. 27-41, https://revistas.uptc.edu.co/index.php/ingenieria/article/view/1337.