Bello, A. ., B. I. Onyeanusi, M. L. Sonfada, J. B. Adeyanju, A. A. Umar, M. A. Umaru, S. A. Shehu, and S. A. Hena. “Histomorphological Studies of the Prenatal Development of Oesophagus of One Humped Camel (camelus Dromedarius)”. Agricultural Advances, vol. 1, no. 4, Sept. 2012, pp. 100-4, http://sjournals.com/index.php/aa/article/view/783.