(1973). Geologic sections, Jackson Purchase region, Kentucky, and adjacent areas. Washington, D C : Department of the Interior.
Lua i Stíl Chicago (17ú heag.)Geologic Sections, Jackson Purchase Region, Kentucky, and Adjacent Areas. Washington, D C : Department of the Interior, 1973.
Lua MLA (9ú heag.)Geologic Sections, Jackson Purchase Region, Kentucky, and Adjacent Areas. Washington, D C : Department of the Interior, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.