Não informado. (2018). Special Publication. University of Kentucky, Kentucky Geological Survey.
Chicago-viite (17. p.)Não informado. Special Publication. Lexington, Ky: University of Kentucky, Kentucky Geological Survey, 2018.
MLA-viite (8. p.)Não informado. Special Publication. University of Kentucky, Kentucky Geological Survey, 2018.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.