Copeland, R. W. (1984). How children learn mathematics: Teaching implications of Piaget's research (4th ed.). Macmillan.
Lua i Stíl Chicago (17ú heag.)Copeland, Richard W. How Children Learn Mathematics: Teaching Implications of Piaget's Research. 4th ed. New York: Macmillan, 1984.
Lua MLA (9ú heag.)Copeland, Richard W. How Children Learn Mathematics: Teaching Implications of Piaget's Research. 4th ed. Macmillan, 1984.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.