LOEVEZINJN, G. B. S. V. Upper Devonian to Lowermost Carboniferous concretion types and their stratigraphic significance (Cantabrian Mountains, N Spain). Trabajos de Geología, [S. l.], v. 17, n. 17, p. 57–67, 1988. DOI: 10.17811/tdg.17.1988.57-67. Disponível em: https://reunido.uniovi.es/index.php/TDG/article/view/2838. Acesso em: 29 mar. 2024.