UHAN, J. Methodological contribution to geochemical subdivision of coal seams . Geologija, [S. l.], v. 37, n. 1, p. 305–319, 1994. DOI: 10.5474/geologija.1995.012. Disponível em: https://www.geologija-revija.si/index.php/geologija/article/view/841. Acesso em: 17 aug. 2022.