ani, ani, Wahidah, Wahidah, AND Mandang, Idris. " Studi Identifikasi Sebaran Ion Logam Pb, Cu, As dan Cd pada Air dan Sedimen di Perairan Bontang Kalimantan Timur Menggunakan Metode Kriging (Ordinary Kriging)" GEOSAINS KUTAI BASIN [Online], Volume 6 Number 1 (28 February 2023)