Sitaraman, Maithreya Aravind. “Symmetrizing Elements of the Kernel to Characterize the Solvability of the σ+ Lights Out Puzzle on Various Geometrical Arrangements”. Minnesota Journal of Undergraduate Mathematics 2, no. 1 (July 1, 2016). Accessed December 4, 2024. https://pubs.lib.umn.edu/index.php/mjum/article/view/4127.