K. Ogundare, S. Agele, and P. Aiyelari, “Organic amendment of an ultisol: effects on soil properties, growth, and yield of maize in Southern Guinea savanna zone of Nigeria”, Int. J. Recycl. Org. Waste Agric., vol. 1, no. 1, Nov. 2012, doi: 10.1186/2251-7715-1-11.