Ugwu, S.; Onyimonyi, A.; Ozor, N.; Mkpado, M. Economics of Alternative Incubation Technology in the Development of Subsistence Poultry Enterprise: Evidence Involving Indigenous Knowledge in Katsina State, Nigeria. Int. J. Poult. Sci. 2009, 8 (3), 277–282. https://doi.org/10.3923/ijps.2009.277.282.