Barrow, J. D. (1992). Pi in the sky: Counting, thinking, and being (First edition. pbk. edition.). Little Brown and Company.
Chicago-čujuhus (17. p.)Barrow, John D. Pi in the Sky: Counting, Thinking, and Being. First edition. pbk. edition. Boston: Little Brown and Company, 1992.
MLA-čujuhus (9. p.)Barrow, John D. Pi in the Sky: Counting, Thinking, and Being. First edition. pbk. edition. Little Brown and Company, 1992.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.