1. Safety and stability for foster children: The policy context;Allen;The Future of Children,2004
2. Annie E. Casey Foundation (nd). KIDS COUNT data center. Retrieved from http://www.datacenter.kidscount.org.
3. Foster care today;Barbell,2001
4. Classification and regression trees;Breiman,1984
5. Casey Family Programs (2010). The state child welfare policy database. Retrieved from http://www.childwelfarepolicy.org/maps.