“Analysis of Productivity Synchronization of Barge Transportation Equipment and Crane Loading on Nickel Ore Delivery Activities in PT. Antam Nickel UBP North Maluku: Analisis Sinkronisasi Produktivitas Alat Angkut Tongkang dan Alat Muat Crane pada Kegiatan Pengapalan Nickel Ore di PT. Antam UBP Nikel Maluku Utara” (2022) JURNAL GEOCELEBES, 6(2), pp. 179 – 186. doi:10.20956/geocelebes.v6i2.22043.