Cole, Cole and Lightfoot:: The development of children, 2005. Worth Publishers. 5. ed.
Lerner, R. M.: Concepts and theories of human development, 2002. Lawrens Earlbaum Associates. 3.ed, Kap: 4, 5, 10, 15, 16, 17, 18.
Sattler, J. M.: Assessment of children. Cognitive Applications, 2001. J. M. Sattler, Publishers, Inc.,San Diego. Fourth Edition.
Hundeide, K.: Barns livsverden: Sosiokulturelle rammer for barns utvikling, 2003. Cappelen Akademiske Forlag.