Minardi, Suhayat, 		Hiden, Hiden, 		Dahrin, Daharta, AND 		Yusuf, Mahmud.
" Analysis of Groundwater Decline and Land Subsidence by using of Microgravity and Vertical Gravity Gradient Over Time Method" <em>Jurnal ILMU DASAR</em> [Online], Volume 15 Number 1 (7 August 2014)