Marshall, D. C., Odell, E., & Starbird, M. P. (2007). Number theory through inquiry. Mathematical Association of America.

Marshall, David C., E. Odell, and Michael P. Starbird. Number Theory Through Inquiry. Washington, D.C.: Mathematical Association of America, 2007.

Marshall, David C., et al. Number Theory Through Inquiry. Mathematical Association of America, 2007.