An Appalachian isochron: a kaolinized carboniferous air-fall volcanic-ash deposit (tonstein) - Lyons, Paul C.; Outerbridge, William F.; Triplehorn, D. M.; Evans, Howard D., jr.; Congdon, Roger D.; Capiro, Mirtha; Hess, Jürgen C.; Nash, William P. (The Geological Society of America bulletin, 1992)
Elektronische Reproduktion der Druck-Ausgabe 1. Juni 2017