Sarsito, D. A., H. Andreas, H. Z. Abidin, M. Gamal, O. K. Suganda, and M. Hendrasto. “Deformation Study of Papandayan Volcano Using GPS Survey Method and Its Correlation With Seismic Data Observation”. Journal of Engineering and Technological Sciences, vol. 38, no. 2, Jan. 2014, pp. 123-46, doi:10.5614/itbj.eng.sci.2006.38.2.4.