Norin, Sergey, Bruce Reed, Andrew Thomason, and David R. Wood. “A Lower Bound on the Average Degree Forcing a Minor”. The Electronic Journal of Combinatorics 27, no. 2 (April 3, 2020): P2.4. Accessed April 7, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v27i2p4.