Cooray, P. G. (2013). The Geological Sciences in the Service of Nigeria. University of Ife Press.
Chicago-čujuhus (17. p.)Cooray, P. G. The Geological Sciences in the Service of Nigeria. University of Ife Press, 2013.
MLA-čujuhus (9. p.)Cooray, P. G. The Geological Sciences in the Service of Nigeria. University of Ife Press, 2013.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.