V. Gowri, K. P. Venkiteswaran, I. Al-Zakwani, J. Mathew, K. Abdul Rahman, and M. Al-Marhoon, “Comparison of the Demographics, Semen Parameters and Hormone Profiles in Men with Primary and Secondary Infertility”, Sultan Qaboos Univ Med J, vol. 10, no. 3, pp. 350–353, Dec. 2010.