Reconnaissance map of potential volcanic hazards from Cotopaxi volcano, Ecuador = Mapa de reconocimiento de riesgos volcanicos potenciales del volcan Cotopaxi, Ecuador / 
Miller, C. Dan.
Hall, Minard L.
Mullineaux, Donal R.
Reston :  U.S. Geological Survey, 
1978.
U.S.G.S. miscellaneous investigations series MAP I-1072.