Mason, J., Graham, A., & Johnston-Wilder, S. (2005). Developing thinking in algebra. Open University in association with Paul Chapman Pub. ; Sage Publications.

Mason, John, Alan Graham, and Sue Johnston-Wilder. Developing Thinking in Algebra. London : Thousand Oaks, Calif.: Open University in association with Paul Chapman Pub. ; Sage Publications, 2005.

Mason, John, et al. Developing Thinking in Algebra. Open University in association with Paul Chapman Pub. ; Sage Publications, 2005.