León, Adan Yovani, and Martha Josefina Parra. “Determination of Molecular Weight of Vacuum Residue and Their SARA Fractions”. CT&F - Ciencia, Tecnología y Futuro 4, no. 2 (December 15, 2010): 101–112. Accessed February 28, 2026. https://ctyfjournalecopetrolcomco.biteca.online/index.php/ctyf/article/view/291.