APA (7th ed.) Citation

United States. Postmaster General. (1930). "Graf Zeppelin" Europe-Pan America round flight. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. "Graf Zeppelin" Europe-Pan America Round Flight. Washington: U.S. GPO, 1930.

MLA (9th ed.) Citation

United States. Postmaster General. "Graf Zeppelin" Europe-Pan America Round Flight. U.S. GPO, 1930.

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