UFO Journal Article: “UFOs IN AND OVER PUERTO RICO’S NATIONAL FOREST (EL YUNQUE)”

By Jorge Martín,
Flying Saucer Review (UK), Volume 44, No. 1, 1999

Source: ignaciodarnaude.com

Jorge Martín is a Puerto Rican UFO researcher:

http://www.ignaciodarnaude.com/avistamientos_ovnis/Martin,UFO%20Photos,Puerto%20Rico,FSR1999V44N1.pdf

Map of El Yunque Caribbean National Forest, Puerto Rico 
(fossweb.com image)