Wright, R. J., Martland, J., Stafford, A. K., & Stanger, G. (2006). Teaching number: Advancing children's skills and strategies (2nd edition.). P. Chapman Pub. ; SAGE Pblications.

Wright, Robert J., Jim Martland, Ann K. Stafford, and Garry Stanger. Teaching Number: Advancing Children's Skills and Strategies. 2nd edition. London ; Thousand Oaks, Calif.: P. Chapman Pub. ; SAGE Pblications, 2006.

Wright, Robert J., et al. Teaching Number: Advancing Children's Skills and Strategies. 2nd edition. P. Chapman Pub. ; SAGE Pblications, 2006.