APA (7th ed.) Citation

United States. Post Office Department. (1920). Scheme of Omaha, Nebr., for use in Railway Mail Service. GPO.

Chicago Style (17th ed.) Citation

United States. Post Office Department. Scheme of Omaha, Nebr., for Use in Railway Mail Service. [Washington]: GPO, 1920.

MLA (9th ed.) Citation

United States. Post Office Department. Scheme of Omaha, Nebr., for Use in Railway Mail Service. GPO, 1920.

Warning: These citations may not always be 100% accurate.