Singmaster, III, James A. “Contaminants in Aged Pesticide Grade Dichloromethane Interfering in Herbicide Residue Analysis and a Method for Their Removal”. The Journal of Agriculture of the University of Puerto Rico 75, no. 4 (October 1, 1991): 329–344. Accessed April 20, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/3619.