BRADY, Lawrence L.; HATCH, Joseph R. Chemical Analyses of Middle and Upper Pennsylvanian Coals from Southeastern Kansas. Current Research in Earth Sciences, [S. l.], n. 240, p. 43–65, 1997. DOI: 10.17161/cres.v0i240.11779. Disponível em: https://journals.ku.edu/cres/article/view/11779.. Acesso em: 6 may. 2024.