Robert M. Liebert, R. W. N. Developmental psychology. Prentice.
Lua i Stíl Chicago (17ú heag.)Robert M. Liebert, Rita Wicks Nelson. Developmental Psychology. Prentice.
Lua MLA (8ú heag.)Robert M. Liebert, Rita Wicks Nelson. Developmental Psychology. Prentice.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.