Child Development Info. (2010). Birth Order. Retrieved July 10, 2011, from Child Development Institute: http://www.childdevelopmentinfo.com/development/birth_order.shtml.
Hartshorne, J.K. (2010). How birth order affects your personalitly. Retrieved July 10, 2011, from Scientific American: http://www.scientificamerican.com/article.cfm?id=ruled-by-birth-order.
Kluger, J. (2006, July). The New Science of Siblings. Retrieved July 10, 2011, from Pleasanton: http://www.pleasanton.k12.ca.us/avhsweb/emersond/appsych/ch11_development/sibs.pdf.
Kluger, J. (2007). The power of birth order. Retrieved July 10, 2011, from Time: http://www.time.com/time/magazine/article/0,9171,1673284,00.html.