1. Regional stratigraphy and petroleum systems of the Appalachian Basin, North America Author/Creator: Swezey, C. (Christopher) Publication/Creation: Denver : For sale by U.S. Geological Survey, Information Services Resource Type: Map Access & Availability: Loading
2. Revised correlation chart of coal beds, coal zones, and key stratigraphic units in the Pennsylvanian rocks of eastern Kentucky Author/Creator: Geological Survey (U.S.) Publication/Creation: Denver, CO : For sale by Map Distribution Resource Type: Map Access & Availability: Loading