APA (7th ed.) Citation

United States. Army Map Service. (1954). El Salvador 1: 50,000 (Ed.1-AMS.). The Service.

Chicago Style (17th ed.) Citation

United States. Army Map Service. El Salvador 1: 50,000. Ed.1-AMS. [Washington, D.C.?]: The Service, 1954.

MLA (8th ed.) Citation

United States. Army Map Service. El Salvador 1: 50,000. Ed.1-AMS. The Service, 1954.