APA
Barker L., Cottingham P., United States of America. Department of the Interior & Cottingham P. (1973). Refining improvement of shale-oil naphtha. United States of America: Bureau of Mines.
Chicago
Barker L.K, Cottingham P.L, United States of America. Department of the Interior and Cottingham P.L. 1973. Refining improvement of shale-oil naphtha. United States of America: Bureau of Mines.
Harvard
Barker L., Cottingham P., United States of America. Department of the Interior and Cottingham P. (1973). Refining improvement of shale-oil naphtha. United States of America: Bureau of Mines.
MLA
Barker L.K, Cottingham P.L, United States of America. Department of the Interior and Cottingham P.L. Refining improvement of shale-oil naphtha. United States of America: Bureau of Mines. 1973.