National Council of Teachers of Mathematics, Dalton, L. C., & Snyder, H. D. (1983). Topics for mathematics clubs (2nd ed.). National Council of Teachers of Mathematics : Mu Alpha Theta.

National Council of Teachers of Mathematics, LeRoy C. Dalton, and Henry D. Snyder. Topics for Mathematics Clubs. 2nd ed. Reston, Va. : [Norman, Okla.]: National Council of Teachers of Mathematics : Mu Alpha Theta, 1983.

National Council of Teachers of Mathematics, et al. Topics for Mathematics Clubs. 2nd ed. National Council of Teachers of Mathematics : Mu Alpha Theta, 1983.