Gaya APA

Information, L, E., Batubara, P, T. (1978). A Review of Mining Studies for The Expansion of Ombilin Coal Mines . : Unit Produksi Ombilin;Balai Penelitian Tambang & Pengolahan Bahan Galian.

Gaya MLA

Information, Lurgi, Express., Batubara, P.N., Tambang. "A Review of Mining Studies for The Expansion of Ombilin Coal Mines". : Unit Produksi Ombilin;Balai Penelitian Tambang & Pengolahan Bahan Galian, 1978. Text.