Indriana, R. D., Brotopuspito, K. S., Setiawan, A., & Soenantyo, T. A. (2018). Pre and post Mount Merapi eruption of free air anomaly in 2010. International Journal of Physical Sciences and Engineering, 2(3), 70–76. https://doi.org/10.29332/ijpse.v2n3.231