WARD, Dwight E.; GOLDSMITH, Richard; CRUZ B., Jaime; RESTREPO A., Hernán. Mineral resources of the departments of Norte de Santander and Santander. Boletín Geológico, [S. l.], v. 18, n. 3, p. 1–140, 1970. DOI: 10.32685/0120-1425/bolgeol18.3.1970.256. Disponível em: https://revistas.sgc.gov.co/index.php/boletingeo/article/view/256. Acesso em: 9 nov. 2026.