6Aassve,A., A. Goisis & M. Sironi 2012, " Happiness and Childbearing across Europe. " Social Indicator Research 108.
7Angrist,J. D. & W. N. Evans 1998, "Children and Their Parents' Labor Supply: Evidence from Exogenous Variation in Family Size. "American Economic Review 88.
8Arnold, F. & Z. Liu 1986, "Sex Preference, Fertility, and Family Planning in China. "Population and Development Review 12.
9Baranowska, A. & A. Matysiak 2011 ," Does Parenthood Increase Happiness? Evidence for Poland. " Vienna Yearbook of Population Research 9.
10Becker, Gary S. 1981. A Treatise on the Family. Cambridge, MA:Harvard University Press.