Gaya APA
Copeland, R, W. (1979).
How children learn mathematics: teching implications of piaget's research (3rd ed.).
New York:
Macmillan Publishing Co., Inc..
Gaya MLA
Copeland, Richard, W..
"How children learn mathematics: teching implications of piaget's research".
3rd ed.
New York:
Macmillan Publishing Co., Inc.,
1979.
Text.