61 books • 1 series
Report of Progress 1874-1889, A-Z. (Volume 4)
Report of Progress 1874-1889, A-Z. (Volume 5)
Report of Progress 1874-1889, A-Z. (Volume 3, PT. 6)
Annual Report of the Geological Survey of Pennsylvania for (Volume 1)
Annual Report on the Geological Survey of Pennsylvania (Volume 3)
Report of Progress 1874-1889, A-Z. (Volume 4, V. 1)
Report of Progress Volume 3
Report of Progress (Volume 1)
Report of Progress 1874-1889, A-Z (Volume 1-2)
Report of Progress (Volume 2, PT. 1)
The Geology of Pennsylvania (Volume 2); A Government Survey
Annual Report of the Geological Survey of Pennsylvania for 1886
A General Index of the Final Summary Report of the Geology of Pennsylvania