Lugo Martinez, W. A.; Avila Rios, H. Y.; Vanegas Chamorro, M. C.; Albis Arrieta, A.; Ardila Barragán, M. A. Evaluation of Demineralization of Semi-Anthracites from Mines Located in Boyacá and Santander (Colombia). Inge Cuc 2019, 15, 48-55.