Novrinda, Riza, and Irfan Saputra. 2017. “Analisis Kemantapan Lereng Kuari Batugamping Di Tuban II PT. United Tractors Semen Gresik Tuban Jawa Timur”. ReTII, March. //journal.itny.ac.id/index.php/ReTII/article/view/509.