STEFANOVA, M.; MARINOV, S. ORGANIC GEOCHEMISTRY OF HUMIC ACIDS FROM A NEOGENE LIGNITE SAMPLE, BULGARIA. Bulletin of the Geological Society of Greece, [S. l.], v. 43, n. 5, p. 2398–2405, 2010. DOI: 10.12681/bgsg.11640. Disponível em: https://ejournals.epublishing.ekt.gr/index.php/geosociety/article/view/11640. Acesso em: 22 nov. 2024.