APA (7 ম সংস্করণ) উদ্ধৃতি

Simpson, A. (1954). The Nigerian coalfield: The geology of parts of Onitsha, Owerri, and Benue Provinces. By authority of the Nigerian Govt..

শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতি

Simpson, A. The Nigerian Coalfield: The Geology of Parts of Onitsha, Owerri, and Benue Provinces. [Zaria]: By authority of the Nigerian Govt., 1954.

M.L.A (8 ম সংস্করণ) উদ্ধৃতি

Simpson, A. The Nigerian Coalfield: The Geology of Parts of Onitsha, Owerri, and Benue Provinces. By authority of the Nigerian Govt., 1954.