Geology of the Bedford shale and Berea sandstone in the Appalachian basin a study of the stratigraphy, sedimentation and paleogeography of rocks of Bedford and Berea age in Ohio and adjacent States - Pepper, James F.; De Witt, Wallace; Demarest, David F. (U.S. Gov. Print. Off., 1954)
Literaturverz. S. 107 - 109