1. Subvolcanic degassing of magma. Magmatic Contributions to hydrothermal systems and the behavior of volatiles in magma;Anderson;Geol. Surv. Jpn. Rep.,1991
2. Gas chemistry and isotopic signature of fumaroles at Galeras Volcano, Colombia;Arehart,1995
3. Actividades y datos obtenidos en el muestreo de fumarolas en los volcanes Puracé, Galeras y Cumbal;Calvache;INGEOMINAS Intern. Rep.,1988
4. La reactivación del Volcán Galeras, Colombia;Cepeda,1989
5. The chemical and isotopic composition of fumarolic gases and spring discharges from Galeras Volcano, Colombia;Fischer,1997