Figarella, Jacinto, Fernando Abruña, and José Vicente-Chandler. 1972. “Effect of Five Nitrogen Sources Applied at Four Rates to Pangola Grass Sod Under Humid Tropical Conditions”. The Journal of Agriculture of the University of Puerto Rico 56 (4):410-16. https://doi.org/10.46429/jaupr.v56i4.10803.