Guan, Huanhuan, Pingzhi Yuan, and Xiangneng Zeng. “A Generalization of Graham’s Conjecture”. The Electronic Journal of Combinatorics 22, no. 4 (October 16, 2015): P4.7. Accessed April 7, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v22i4p7.