“ESTIMASI GEOLOGICAL STRENGTH INDEX (GSI) SYSTEM PADA LAPISAN BATUGAMPING BERONGGA DI TAMBANG KUARI BLOK SAWIR TUBAN JAWA TIMUR”. PROMINE 2, no. 2 (August 14, 2018). Accessed April 13, 2026. https://www.journal.ubb.ac.id/index.php/promine/article/view/76.