Gaya APA

Associates, L, &., Associates, A, M, &. (1982). Ombilin II Integrated Coal Mining Project Central-West Sumatra . : Layton & Macknight.

Gaya MLA

Associates, Layton, &., Associates, Alex, Macknight, &. "Ombilin II Integrated Coal Mining Project Central-West Sumatra". : Layton & Macknight, 1982. Batubara.