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.
Lua i Stíl Chicago (17ú heag.)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.
Lua MLA (8ú heag.)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.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.