Stern, C. (1949). Children discover arithmetic: An introduction to structural arithmetic. Harper.
Cita Chicago (17th ed.)Stern, Catherine. Children Discover Arithmetic: An Introduction to Structural Arithmetic. New York: Harper, 1949.
Cita MLA (9th ed.)Stern, Catherine. Children Discover Arithmetic: An Introduction to Structural Arithmetic. Harper, 1949.
Atenció: Aquestes cites poden no estar 100% correctes.