Gaya APA

Johnson, C. (1984). An Introducction to The North Sumatera Geochemical And Mineral Exploration Project (NSGMEP) Cifer 1887 Microcomputer . Bandung: Pusat Sumber Daya Geologi.

Gaya MLA

Johnson, C.C. "An Introducction to The North Sumatera Geochemical And Mineral Exploration Project (NSGMEP) Cifer 1887 Microcomputer". Bandung: Pusat Sumber Daya Geologi, 1984. Geokimia.