Kang, Liying, and Vladimir Nikiforov. “Extremal Problems for the $p$-Spectral Radius of Graphs”. The Electronic Journal of Combinatorics 21, no. 3 (August 6, 2014): P3.21. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v21i3p21.