Cita APA (7th ed.)
Heddens, J. W. (1979). Todays mathematics: Concepts and methods in elementary school mathematics (4th ed.). S.R.A.
Cita Chicago (17th ed.)
Heddens, James W. Todays Mathematics: Concepts and Methods in Elementary School Mathematics. 4th ed. Chicago: S.R.A, 1979.
Cita MLA (9th ed.)
Heddens, James W. Todays Mathematics: Concepts and Methods in Elementary School Mathematics. 4th ed. S.R.A, 1979.
Atenció: Aquestes cites poden no estar 100% correctes.