APA (7e ed.) Bronvermelding

Barrow, J. D. (1992). Pi in the sky: Counting, thinking, and being (First edition. pbk. edition.). Little Brown and Company.

Chicago (17e ed.) Bronvermelding

Barrow, John D. Pi in the Sky: Counting, Thinking, and Being. First edition. pbk. edition. Boston: Little Brown and Company, 1992.

MLA (9e ed.) Bronvermelding

Barrow, John D. Pi in the Sky: Counting, Thinking, and Being. First edition. pbk. edition. Little Brown and Company, 1992.