Achmad Reza Kurniawan, and Nur Ali Amri. “Resource Estimation Using Ordinary Kriging on Pit X, PT. Indo Muro Kencana, Tanah Siang District, Murung Raya Regency, Kaliamtan Tengah”. ReTII, Nov. 2019, pp. 59-69, //journal.itny.ac.id/index.php/ReTII/article/view/1460.