Caro-Costas, R. et al. 1972. Effect of Four Levels of Concentrate Feeding on Milk Production by Holstein Cows Grazing Intensively Managed Tropical Grass Pastures. The Journal of Agriculture of the University of Puerto Rico. 56, 2 (Apr. 1972), 97–103. DOI:https://doi.org/10.46429/jaupr.v56i2.10853.