APA (7th ed.) Citation

Whitney, N., & Branton, L. (1977). The sky's the limit. Heinemann Educational Books.

Chicago Style (17th ed.) Citation

Whitney, Norman, and Leslie Branton. The Sky's the Limit. London: Heinemann Educational Books, 1977.

MLA (9th ed.) Citation

Whitney, Norman, and Leslie Branton. The Sky's the Limit. Heinemann Educational Books, 1977.