Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, IndonesiaYunus Daud, Syamsu Rosid, Fikri Fahmi, Faris Maulana Yunus and Reza MuflihendriE3S Web Conf., 31 (2018) 02003DOI: https://doi.org/10.1051/e3sconf/20183102003