Monsalve, María Luisa, and Bernardo Pulgarín. “Los Coconucos Volcanic Chain (Colombia): Eruptive Centers and Recent Products”. Boletín Geológico, vol. 37, no. 1-3, Jan. 1999, pp. 16-51, doi:10.32685/0120-1425/bolgeol37.1-3.1999.38.