APA (7th ed.) Citation

Ruppelt, E. J. (1956). The report on unidentified flying objects. Ace Books.

Chicago Style (17th ed.) Citation

Ruppelt, Edward J. The Report on Unidentified Flying Objects. New York: Ace Books, 1956.

MLA (9th ed.) Citation

Ruppelt, Edward J. The Report on Unidentified Flying Objects. Ace Books, 1956.