School Mathematics Study Group & Schaaf, W. L. (1967). Nature and history of Pi. Leland Stanford Junior University.
Čikaški stil citiranja (17. izdanje)School Mathematics Study Group i William L. Schaaf. Nature and History of Pi. Stanford, CA: Leland Stanford Junior University, 1967.
MLA način citiranja (9. izdanje)School Mathematics Study Group i William L. Schaaf. Nature and History of Pi. Leland Stanford Junior University, 1967.
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