Gaya APA

Inc, J, W, &, S. (1991). Report On Exploration Of Entral Sumatra Coal Exploration Project . Bandung: John Wiley & Sons. Inc.

Gaya MLA

Inc, John, Wiley, &, Sons.. "Report On Exploration Of Entral Sumatra Coal Exploration Project". Bandung: John Wiley & Sons. Inc, 1991. Batubara.