Stern, C. (1949). Children discover arithmetic: An introduction to structural arithmetic. Harper.
Citazione stile Chigago Style (17a edizione)Stern, Catherine. Children Discover Arithmetic: An Introduction to Structural Arithmetic. New York: Harper, 1949.
Citatione MLA (9a ed.)Stern, Catherine. Children Discover Arithmetic: An Introduction to Structural Arithmetic. Harper, 1949.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.