Le, T. A., and J. W. Sander. “Integral Circulant Ramanujan Graphs of Prime Power Order”. The Electronic Journal of Combinatorics 20, no. 3 (September 6, 2013): P35. Accessed March 28, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v20i3p35.