APA (7th ed.) Citation

Heinlein, R. A. (1977). Tunnel in the sky (1st Ballantine books ed.). Ballantine Books.

Chicago Style (17th ed.) Citation

Heinlein, Robert A. Tunnel in the Sky. 1st Ballantine books ed. New York: Ballantine Books, 1977.

MLA (9th ed.) Citation

Heinlein, Robert A. Tunnel in the Sky. 1st Ballantine books ed. Ballantine Books, 1977.

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