Harris, H. H. (1959). The history and calculation of pi. Graduate Division of the Kansas State Teachers College.
Chicago-viite (17. p.)Harris, Herman H. The History and Calculation of Pi. Emporia: Graduate Division of the Kansas State Teachers College, 1959.
MLA-viite (8. p.)Harris, Herman H. The History and Calculation of Pi. Graduate Division of the Kansas State Teachers College, 1959.
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