nikoopour, H. (2005). The institutional classification of various social security systems. Social Security Journal, 7(3), 5–24.

nikoopour, H. "The institutional classification of various social security systems", Social Security Journal, 7, 3, 2005, 5–24.

nikoopour, H. (2005). 'The institutional classification of various social security systems', Social Security Journal, 7(3), pp. 5–24.

nikoopour, H., "The institutional classification of various social security systems." Social Security Journal, 7 3 (2005): 5–24,

nikoopour H. The institutional classification of various social security systems. Social Security Journal. 2005;7(3):5–24 (In Persian).