School Mathematics Study Group & Schaaf, W. L. (1967). Nature and history of Pi. Leland Stanford Junior University.
芝加哥风格引文School Mathematics Study Group 与 William L. Schaaf. Nature and History of Pi. Stanford, CA: Leland Stanford Junior University, 1967.
MLA引文School Mathematics Study Group 与 William L. Schaaf. Nature and History of Pi. Leland Stanford Junior University, 1967.
警告：这些引文格式不一定是100％准确.