Schubert, T.H. and Zambrana, J.A. 1982. Araucaria heterophylla and Pinus caribaea: potential Christmas trees for Puerto Rico. The Journal of Agriculture of the University of Puerto Rico. 66, 2 (Apr. 1982), 145–149. DOI:https://doi.org/10.46429/jaupr.v66i2.7658.