National Council of Teachers of Mathematics. (1954). The Arithmetic teacher. National Council of Teachers of Mathematics.
Cita Chicago (17th ed.)National Council of Teachers of Mathematics. The Arithmetic Teacher. Washington, D.C: National Council of Teachers of Mathematics, 1954.
Cita MLA (9th ed.)National Council of Teachers of Mathematics. The Arithmetic Teacher. National Council of Teachers of Mathematics, 1954.
Atenció: Aquestes cites poden no estar 100% correctes.