National Council of Teachers of Mathematics. (1954). The Arithmetic teacher. National Council of Teachers of Mathematics.
Chicago-Zitierstil (17. Ausg.)National Council of Teachers of Mathematics. The Arithmetic Teacher. Washington, D.C: National Council of Teachers of Mathematics, 1954.
MLA-Zitierstil (9. Ausg.)National Council of Teachers of Mathematics. The Arithmetic Teacher. National Council of Teachers of Mathematics, 1954.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.