Ingersoll, G. E. (1932). Hand methods of placer mining and placer mining districts of Washington and Oregon. State College of Washington.
Cita Chicago Style (17a ed.)Ingersoll, Guy Ernest. Hand Methods of Placer Mining and Placer Mining Districts of Washington and Oregon. [Pullman: State College of Washington, 1932.
Cita MLA (8a ed.)Ingersoll, Guy Ernest. Hand Methods of Placer Mining and Placer Mining Districts of Washington and Oregon. State College of Washington, 1932.
Precaución: Estas citas no son 100% exactas.