Lai, Chunhui. “A Lower Bound for the Number of Edges in a Graph Containing No Two Cycles of the Same Length”. The Electronic Journal of Combinatorics 8, no. 1 (October 20, 2001): N9. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v8i1n9.