SAWIN, Robert S.; WEST, Ronald R.; FRANSEEN, Evan K.; WATNEY, W. Lynn; MCCAULEY, James R. Carboniferous–Permian Boundary in Kansas, Midcontinent, U.S.A. Current Research in Earth Sciences, [S. l.], n. 252, p. 1–13, 2006. DOI: 10.17161/cres.v0i252.11838. Disponível em: https://journals.ku.edu/cres/article/view/11838.. Acesso em: 4 may. 2024.