Wolcott, G.N. and Seín, Jr., F. 1933. A YEAR’S EXPERIENCE WITH THE COTTONY CUSHION SCALE IN PUERTO RICO. The Journal of Agriculture of the University of Puerto Rico. 17, 3 (Jul. 1933), 199–221. DOI:https://doi.org/10.46429/jaupr.v17i3.14252.