1. Stratigraphy of the Pennsylvanian and Permian systems of the Central Appalachians;Arkle,1974
2. Implications for organic maturation studies of evidence for a geologically rapid increase and stabilization of vitrinite reflectance at peak temperature: Cerro Prieto geothermal system, Mexico;Barker;Amer. Assoc. Petro. Geol. Bull.,1991
3. Coalification patterns of the Pittsburgh coal: their origin and bearing on hydrocarbon maturation;Chyi;Int. J. Coal Geol.,1987
4. Regional coalification patterns for the coals of eastern Kentucky, Virginia, West Virginia, Ohio, Maryland, and southern Pennsylvania;Cole,1979