Gaya APA

Wanless, H, R. (1946). Pennsylvanian Geology of a Part of the Southern Appalachian Coal Field . United States of America: Waverly Press,Inc..

Gaya MLA

Wanless, Harold,, R.. "Pennsylvanian Geology of a Part of the Southern Appalachian Coal Field". United States of America: Waverly Press,Inc., 1946. Text.