31. Geologic map of the Balkan quadrangle, Bell and Harlan counties, Kentucky [cartographic material]
1973. 2012-04-13T15:43:39Z. 2012-04-16T15:59:13Z. Froelich, A. J. (Albert Joseph), 1929-. U.S. Geological Survey. English. Public. Kentucky, Bell County, and Harlan County.