Cotter, E., 1983. Shelf, Paralic and Fluvial environments, and Eustatic Sea-level Fluctuations in the Origin of the Tuscarora Formation (Lower Silurian) Of Central Pennsylvania. Journal of Sedimentary Petrology, v. 53, p. 25-49.
Eckel, E.C., 1914. Iron Ores. McGraw-Hill Book Co., York, Pa. 430 p.
From the Pennsylvania Department of Transportation, this report is three volumes from 1996 detailing geology, water, and other environmental features along the State Rt 220 from Bald Eagle to Matternville.