Citazione Stile APA (7a Edizione)

UNDERHILL, R. G. (1977). Teaching elementary school mathematics.-- ed.2. Charles E.Merill pub.

Citazione stile Chigago Style (17a edizione)

UNDERHILL, Robert G. Teaching Elementary School Mathematics.-- Ed.2. Columbus: Charles E.Merill pub, 1977.

Citatione MLA (9a ed.)

UNDERHILL, Robert G. Teaching Elementary School Mathematics.-- Ed.2. Charles E.Merill pub, 1977.