United Nations. Technical Assistance Administration & Ortiz, R. M. (1954). The harbor system of El Salvador: Prepared for the Government of El Salvador by Ricardo M. Ortiz.
Chicago-viite (17. p.)United Nations. Technical Assistance Administration ja Ricardo M. Ortiz. The Harbor System of El Salvador: Prepared for the Government of El Salvador by Ricardo M. Ortiz. New York, 1954.
MLA-viite (9. p.)United Nations. Technical Assistance Administration ja Ricardo M. Ortiz. The Harbor System of El Salvador: Prepared for the Government of El Salvador by Ricardo M. Ortiz. 1954.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.