O. J. Owen, E. Ngodigha, and A. Amakiri, “Proximate Composition of Heat Treated Poultry Litter (Layers)”, Int. J. Poult. Sci., vol. 7, no. 11, pp. 1033–1035, Oct. 2008, doi: 10.3923/ijps.2008.1033.1035.