Copeland, R. W. (1974). How children learn mathematics: Teaching implications of piaget's research (2nd ed.). Macmillan.
Lua i Stíl Chicago (17ú heag.)Copeland, Richard W. How Children Learn Mathematics: Teaching Implications of Piaget's Research. 2nd ed. New York: Macmillan, 1974.
Lua MLA (9ú heag.)Copeland, Richard W. How Children Learn Mathematics: Teaching Implications of Piaget's Research. 2nd ed. Macmillan, 1974.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.