Priatna, P. and Kadarsetia, E. 2007. Characteristics of volcanic gas correlated to the eruption activity; Case study in the Merapi Volcano, periods of 1990-1994. Indonesian Journal on Geoscience. 2, 4 (Dec. 2007), 235–246. DOI:https://doi.org/10.17014/ijog.2.4.235-246.