Yuliana, Yuliana, 		Djayus, Djayus, 		Munir, Rahmiati, AND 		supriyanto, Supriyanto.
" ANALISIS HUBUNGAN NILAI HGI (HARDGROVE GRINDABILITY INDEX) ASH CONTENT INHERENT MOISTURE DAN TOTAL SULFUR TERHADAP NILAI KALORI BATUBARA DI PT. GEOSERVICES SAMARINDA KALIMANTAN TIMUR" <em>GEOSAINS KUTAI BASIN</em> [Online], Volume 5 Number 1 (18 August 2022)