Danforth, Stuart T. “ORNITHOLOGICAL INVESTIGATIONS IN VIEQUES ISLAND, PUERTO RICO, DURING DECEMBER, 1935”. The Journal of Agriculture of the University of Puerto Rico 21, no. 4 (October 1, 1937): 539–550. Accessed April 24, 2024. https://revistas.upr.edu/index.php/jaupr/article/view/14319.