(1973). Geologic sections, Jackson Purchase region, Kentucky, and adjacent areas. Washington, D C : Department of the Interior.
Chicago-viite (17. p.)Geologic Sections, Jackson Purchase Region, Kentucky, and Adjacent Areas. Washington, D C : Department of the Interior, 1973.
MLA-viite (9. p.)Geologic Sections, Jackson Purchase Region, Kentucky, and Adjacent Areas. Washington, D C : Department of the Interior, 1973.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.