Ramirez Caballero, G. E.; Ardila Suárez, C.; Rojas Cristancho, J. Z.; Pineda Martínez, J. P.; Ramírez García, A. Effect of Impurities in the Crude Glycerol Polymerization Reaction to Produce Polyglycerol. CT&F Cienc. Tecnol. Futuro 2019, 9, 89-98.