Al-Zubaidi, U. I. M. . and Fakhrildin, M.-B. M.-R. . (2011) “Influence of different concentrations of Sildenafil Citrate on histological parameters of mice epididymis”, Journal of Biotechnology Research Center, 5(2), pp. 55–60. doi: 10.24126/jobrc.2011.5.2.165.