Camoens, J.K. et al. 1976. Holsteins in Puerto Rico: II. Influence of Lactation Length, Days Dry, Days Open, and Calving Interval on Production Traits. The Journal of Agriculture of the University of Puerto Rico. 60, 4 (Oct. 1976), 540–550. DOI:https://doi.org/10.46429/jaupr.v60i4.10499.