APA (7th ed.) Citation

School Mathematics Study Group & Schaaf, W. L. (1966). Prime numbers and perfect numbers. School Mathematics Study Group.

Chicago Style (17th ed.) Citation

School Mathematics Study Group and William L. Schaaf. Prime Numbers and Perfect Numbers. Stanford, Calif: School Mathematics Study Group, 1966.

MLA (9th ed.) Citation

School Mathematics Study Group and William L. Schaaf. Prime Numbers and Perfect Numbers. School Mathematics Study Group, 1966.