Shahbazian, Roujman. “The Consequence of Birth Spacing for First- and Second-Born siblings’ Long-Term Income Rank: A Restrictive Two-Child Family Approach”. Journal of Family Research 32, no. 1 (January 13, 2020): 72-104. Accessed November 24, 2020. https://ubp.uni-bamberg.de/jfr/index.php/jfr/article/view/159.