Piaget, J. (1960). The child's conception of geometry. Basic books.
Chicago-čujuhus (17. p.)Piaget, Jean. The Child's Conception of Geometry. New York: Basic books, 1960.
MLA-čujuhus (9. p.)Piaget, Jean. The Child's Conception of Geometry. Basic books, 1960.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.