Não informado. (1970). Journal for Research in Mathematics Education. National Council of Teachers of Mathematics.
Chicago-Zitierstil (17. Ausg.)Não informado. Journal for Research in Mathematics Education. Reston, Va: National Council of Teachers of Mathematics, 1970.
MLA-Zitierstil (8. Ausg.)Não informado. Journal for Research in Mathematics Education. National Council of Teachers of Mathematics, 1970.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.