Topographic and Geologic Survey of Pennsylvania Report No. 6: Graphite Deposits of Pennsylvania
By Benjamin L. Miller Harrisburg: C. E. Aughinbaugh, Printer to the State of Pennsylvania, 1912
Public-domain full text preserved in the Mountain Man Mining Library. Original source: archive.org.
Topographic and Geologic Survey of Pennsylvania Report No. 6: Graphite Deposits of Pennsylvania Author: Benjamin L. Miller Year: 1912 Category: Historical By Benjamin L. Miller Harrisburg: C. E. Aughinbaugh, Printer to the State of Pennsylvania, 1912 Tags: archive.org, graphite deposits Source: ://archive.org/details/TopographicAndGeologicSurveyOfPennsylvaniaReportNo.6GraphiteDeposits