APA (7th ed.) Citation

Foley, M., & Hoare, C. A. R. (1971). Proof of a recursive program. Computer Journal, 14, 391. https://doi.org/10.1093/comjnl/14.4.391

Chicago Style (17th ed.) Citation

Foley, M., and C. A. R. Hoare. "Proof of a Recursive Program." Computer Journal 14 (1971): 391. https://doi.org/10.1093/comjnl/14.4.391.

MLA (9th ed.) Citation

Foley, M., and C. A. R. Hoare. "Proof of a Recursive Program." Computer Journal, vol. 14, 1971, p. 391, https://doi.org/10.1093/comjnl/14.4.391.