Cita APA (7th ed.)

Underhill, R. G. (1977). Teaching elementary school mathematics (2nd ed.). Merrill.

Cita Chicago (17th ed.)

Underhill, Robert G. Teaching Elementary School Mathematics. 2nd ed. Columbus: Merrill, 1977.

Cita MLA (9th ed.)

Underhill, Robert G. Teaching Elementary School Mathematics. 2nd ed. Merrill, 1977.