Gardner, Martin. “Some New Results on Magic Hexagrams.” Martin Gardner in the Twenty-First Century, edited by Michael Henle and Brian Hopkins, 1st ed., Mathematical Association of America, 2012, pp. 159–166, www.jstor.org/stable/10.4169/j.ctt13x0ng0.24. Accessed 26 Feb. 2021.
Gardner, M. (2012). Some New Results on Magic Hexagrams. In Henle M. & Hopkins B. (Eds.), Martin Gardner in the Twenty-First Century (pp. 159-166). Mathematical Association of America. Retrieved February 26, 2021, from http://www.jstor.org/stable/10.4169/j.ctt13x0ng0.24
Gardner, Martin. "Some New Results on Magic Hexagrams." In Martin Gardner in the Twenty-First Century, edited by Henle Michael and Hopkins Brian, 159-66. Mathematical Association of America, 2012. Accessed February 26, 2021. http://www.jstor.org/stable/10.4169/j.ctt13x0ng0.24.
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