APA (7th ed.) Citation

Whale, G. (1990). British airships: Past, present and future. Project Gutenberg.

Chicago Style (17th ed.) Citation

Whale, George. British Airships: Past, Present and Future. Champaign, Ill: Project Gutenberg, 1990.

MLA (9th ed.) Citation

Whale, George. British Airships: Past, Present and Future. Project Gutenberg, 1990.

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