Vergleiche
History of Clear Creek and Boulder Valleys, Colorado. Containing a brief history of the State of Colorado [by W. B. Vickers] ... a history of Gilpin, Clear Creek, Boulder and Jefferson Counties [respectively by J. Burrell, A. Frost, A. Bixby and E. L. Berthoud] and biographical sketches
The British Library1880
O. L. Baskin & Co.