Harris, H. H. (1959). The history and calculation of pi. Graduate Division of the Kansas State Teachers College.
Lua i Stíl Chicago (17ú heag.)Harris, Herman H. The History and Calculation of Pi. Emporia: Graduate Division of the Kansas State Teachers College, 1959.
Lua MLA (8ú heag.)Harris, Herman H. The History and Calculation of Pi. Graduate Division of the Kansas State Teachers College, 1959.
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