APA (7th ed.) Citation

(1928). Chronology of U.S. air transport; Mail routes contracted but not in service yet. [publisher not identified].

Chicago Style (17th ed.) Citation

Chronology of U.S. Air Transport; Mail Routes Contracted but Not in Service yet. [Washington]: [publisher not identified], 1928.

MLA (9th ed.) Citation

Chronology of U.S. Air Transport; Mail Routes Contracted but Not in Service yet. [publisher not identified], 1928.