Παραπομπή σε μορφή APA (7η εκδ.)

O'Harra, C. C. (1899). Notes on the geology and mineral deposits of a portion of the southern Black Hills. South Dakota School of Mines.

Παραπομπή σε μορφή Chicago (17η εκδ.)

O'Harra, Cleophas C. Notes on the Geology and Mineral Deposits of a Portion of the Southern Black Hills. Rapid City, S. D.: South Dakota School of Mines, 1899.

Παραπομπή σε μορφή MLA (8th εκδ.)

O'Harra, Cleophas C. Notes on the Geology and Mineral Deposits of a Portion of the Southern Black Hills. South Dakota School of Mines, 1899.