Perez, Y, A Gonzalez, J Castillo, A Sanchez, P Oliveira, and C Pichara. “Obtaining and Characterization of Pellets Based on Walnut Shells, Waste Paper and Paperboard”. Rev. Téc. Fac. Ing. Univ. Zulia 42, no. 3 (December 17, 2019): 181-186. Accessed August 2, 2025. http://www.produccioncientifica.luz.edu.ve/index.php/tecnica/article/view/30217.