APA (7th ed.) Citation

Lankford, F. G., Heikkinen, D. D., & Silvey, I. M. (1970). Numbers and operations. Harcourt Brace Janovich.

Chicago Style (17th ed.) Citation

Lankford, Francis G., Donald D. Heikkinen, and Ina M. Silvey. Numbers and Operations. New York [u.a.]: Harcourt Brace Janovich, 1970.

MLA (9th ed.) Citation

Lankford, Francis G., et al. Numbers and Operations. Harcourt Brace Janovich, 1970.