Association for Supervision and Curriculum Development. Committee on the Three R's in the Elementary School. (1952). The three R's in the elementary school. s. n.
Cita Chicago (17th ed.)Association for Supervision and Curriculum Development. Committee on the Three R's in the Elementary School. The Three R's in the Elementary School. Washington: s. n, 1952.
Cita MLA (9th ed.)Association for Supervision and Curriculum Development. Committee on the Three R's in the Elementary School. The Three R's in the Elementary School. s. n, 1952.
Atenció: Aquestes cites poden no estar 100% correctes.