KULSTAD, Robert O.; NIXON, E.K. Kansas Pits and Quarries. Bulletin (Kansas Geological Survey), [S. l.], n. 90, p. 1–12, 1951. DOI: 10.17161/kgsbulletin.no.90.22034. Disponível em: https://journals.ku.edu/kgsbulletin/article/view/22034. Acesso em: 6 apr. 2025.