ZHIWEN, L.; JIANHUA, G. Prospect of Middle Ordovician Yanxi Formation Black Shale in South Hunan Province. Journal of Mines, Metals and Fuels, [S. l.], v. 67, n. 9, p. 424–430, 2022. Disponível em: https://www.informaticsjournals.com/index.php/jmmf/article/view/31651. Acesso em: 9 may. 2024.