8 books
Annual Report of the Geological Survey of Pennsylvania for 1886, Vol. 4 of 4: Miscellaneous Reports (Classic Reprint)
The Geology of Lehigh and Northampton Counties, Vol. 1 (Classic Reprint)
Geological Survey of Pennsylvania, Report of Progress, G4: Part I. The Geology of Clinton County; Part II. A Special Study of the Carboniferous and Devonian Strata Along the West Branch of the Susquehanna River (Classic Reprint)
The Resources of Pennsylvania in a Nutshell (Classic Reprint)
Topographic and Geological Survey of Pennsylvania, 1906-1908 (Classic Reprint)
Annual Report of the Geological Survey of Pennsylvania Volume 1
Annual Report of the Geological Survey of Pennsylvania for (Volume 4)
Final Report Ordered by Legislature, 1891. a Summary Description of the Geology of Pennsylvania, in Three Volumes, with a New Geological Map of