Polit (1987). «Only children and personality development: A quantitative review». Journal of Marriage and the Family. 49: 309–325. JSTOR352302. doi:10.2307/352302
Polit (1987). «Only children and personality development: A quantitative review». Journal of Marriage and the Family. 49: 309–325. JSTOR352302. doi:10.2307/352302