Richardson, K. (1998). Models of cognitive development. Psychology Press.
Lua i Stíl Chicago (17ú heag.)Richardson, Ken. Models of Cognitive Development. Hove, East Sussex, UK: Psychology Press, 1998.
Lua MLA (9ú heag.)Richardson, Ken. Models of Cognitive Development. Psychology Press, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.