APA aipamena

Freitag, H. T., & Freitag, A. H. (1960). The number story. National Council of Teachers of Mathematics.

Chicago Style aipamena

Freitag, Herta Taussig, and Arthur H. Freitag. The Number Story. Washington: National Council of Teachers of Mathematics, 1960.

MLA aipamena

Freitag, Herta Taussig, and Arthur H. Freitag. The Number Story. National Council of Teachers of Mathematics, 1960.