Lugo, M. de L., A. González, and R. E. Talbert. “Smooth Pigweed (Amaranthus Hybrids L.) Interference With Snap Bean (Phaseolus Vulgaris L.) Quality”. The Journal of Agriculture of the University of Puerto Rico, vol. 79, no. 3-4, Oct. 1995, pp. 173-9, doi:10.46429/jaupr.v79i3-4.4312.