Ronga, Giovanni. Delia condizione giuridica dei figli nati fuori di matrimonio. Turin, 1873.
Roskovány, Augustine de. Supplementa ad collectiones monumentorum et literaturae de matrimonio in ecclesia catholica. Nitriae, 1887.
Ross, Edward Alsworth. Social Control: A Survey of the Foundations of Order. New York and London, 1901.
Rubin, M., and Westergaard, H. Statistik der Ehen auf Grund der socialen Gliederang der Bevölkerung ... in Dänemark. Jena, 1890.
Russell, Alys. "Social Democracy and the Woman Question in Germany." In Bertrand Russell's German Social Democracy, 173-95. London, New York, and Bombay, 1896.
Ryan, Michael. Lectures on Population, Marriage, and Divorce, as Questions of State Medicine. London, 1831.
Ryan, Michael. The Philosophy of Marriage, in its Social, Moral, and Physical Relations. 3d ed. London, 1839.
St. Bon, Pacoret de. Les institutions de la famille dans le code civil italien. Grenoble, 1878.
Sacchi, A. Il divorzio in Italia. Rome, 1890.
Salmonson, M. From the Marriage License Window. Chicago, 1887.