National Council of Teachers of Mathematics & Steffe, L. P. (1975). Research on the mathematical thinking of young children: Six empirical studies. National Council of Teachers of Mathematics.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Council of Teachers of Mathematics و Leslie P. Steffe. Research on the Mathematical Thinking of Young Children: Six Empirical Studies. Reston, VA: National Council of Teachers of Mathematics, 1975.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)National Council of Teachers of Mathematics و Leslie P. Steffe. Research on the Mathematical Thinking of Young Children: Six Empirical Studies. National Council of Teachers of Mathematics, 1975.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.