1. Acosta, P. (2011). School attendance, child labour, and remittances from international migration in El Salvador. J Dev Stud, 47(6), 913–936. doi: 10.1080/00220388.2011.563298 .
2. Agadjanian, V., & Prata, N. (2002). War, peace, and fertility in Angola. Demography, 39(2), 215–231.
3. Becker, G. S., & Lewis, H. G. (1974). Interaction between quantity and quality of children. Economics of the family: marriage, children, and human capital (pp. 81–90): UMI.
4. Becker, G. S., & Tomes, N. (1976). Child endowments and quantity and quality of children. J Polit Econ, 84(4), S143–S162. doi: 10.1086/260536 .
5. Belsky, J. (1999). Modern evolutionary theory and patterns of attachment. In J. Cassidy & P. R. Shaver (Eds.), Handbook of attachment: theory, research, and clinical applications (pp. 141–161). New York, NY: Guilford Press.