Shipp, D. E., & Adams, S. (1964). Developing arithemetic concepts and skills.
Chicago Edition CitationShipp, Donald E., i Sam Adams. Developing Arithemetic Concepts and Skills. Prentice-Hall Inc., Englewood Cliffs, New Jersy, 1964.
Cita MLAShipp, Donald E., i Sam Adams. Developing Arithemetic Concepts and Skills. 1964.
Atenció: Aquestes cites poden no estar 100% correctes.