APA
Ports Puerto Rico, . (19901993). Ports Puerto Rico. Santurce, P.R: Puerto Rico Almanacs, Inc.
Chicago
Ports Puerto Rico, . 19901993. Ports Puerto Rico. Santurce, P.R: Puerto Rico Almanacs, Inc.
Harvard
Ports Puerto Rico, . (19901993). Ports Puerto Rico. Santurce, P.R: Puerto Rico Almanacs, Inc.
MLA
Ports Puerto Rico, . Ports Puerto Rico. Santurce, P.R: Puerto Rico Almanacs, Inc. 19901993.