National Council of Teachers Mathematics & Steffe, L. P. (1975). Research on mathematical thinking of young children: Six empirical studies. National Council of Teachers of Mathematics.
Citazione stile Chigago Style (17a edizione)National Council of Teachers Mathematics e Leslie P. Steffe. Research on Mathematical Thinking of Young Children: Six Empirical Studies. Reston, Va: National Council of Teachers of Mathematics, 1975.
Citatione MLA (9a ed.)National Council of Teachers Mathematics e Leslie P. Steffe. Research on Mathematical Thinking of Young Children: Six Empirical Studies. National Council of Teachers of Mathematics, 1975.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.