(1972). Fence diagram and geologic column of Pennsylvanian and Upper Mississippian rocks of the Upper Tradewater basin, Kentucky. Washington, D C : United States Department of Interior.
Lua i Stíl Chicago (17ú heag.)Fence Diagram and Geologic Column of Pennsylvanian and Upper Mississippian Rocks of the Upper Tradewater Basin, Kentucky. Washington, D C : United States Department of Interior, 1972.
Lua MLA (9ú heag.)Fence Diagram and Geologic Column of Pennsylvanian and Upper Mississippian Rocks of the Upper Tradewater Basin, Kentucky. Washington, D C : United States Department of Interior, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.