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.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)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.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)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.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.