Não informado. (1954). Records of the Geological Survey of Nigeria. Ministry of Mines and Power.
Chicago-viite (17. p.)Não informado. Records of the Geological Survey of Nigeria. Lagos: Ministry of Mines and Power, 1954.
MLA-viite (8. p.)Não informado. Records of the Geological Survey of Nigeria. Ministry of Mines and Power, 1954.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.