Frost, J. L., Wortham, S. C., & Reifel, R. S. (2012). Play and child development (4th ed.). Pearson.
Lua i Stíl Chicago (17ú heag.)Frost, Joe L., Sue Clark Wortham, agus Robert Stuart Reifel. Play and Child Development. 4th ed. Boston: Pearson, 2012.
Lua MLA (9ú heag.)Frost, Joe L., et al. Play and Child Development. 4th ed. Pearson, 2012.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.