APA

National Council of Teachers of Mathematics, . (1972). Numeros racionales. México: Trillas.

Chicago

National Council of Teachers of Mathematics, . 1972. Numeros racionales. México: Trillas.

Harvard

National Council of Teachers of Mathematics, . (1972). Numeros racionales. México: Trillas.

MLA

National Council of Teachers of Mathematics, . Numeros racionales. México: Trillas. 1972.