Mahdi, Estabraq M. “The Effect of Continuous Darkness and Continuous Light on the Reactivity of Smooth Muscles to Drugs in the Rat Vas Deferens”. AL-Kindy College Medical Journal, vol. 5, no. 1, June 2009, pp. 47-51, https://jkmc.uobaghdad.edu.iq/index.php/MEDICAL/article/view/723.