Gaya APA

Coorporation, T, J, W, E. (). Mining Practice at the Ombilin Coal Mine west - Central Sumatra . New York: The J.G. White Engineering Corp..

Gaya MLA

Coorporation, The, J.G., White, Engineering. "Mining Practice at the Ombilin Coal Mine west - Central Sumatra". New York: The J.G. White Engineering Corp., . Text.