Brückner, Guido, Ignaz Rutter, and Peter Stumpf. “Level-Planarity: Transitivity Vs. Even Crossings”. The Electronic Journal of Combinatorics 29, no. 4 (November 4, 2022): P4.22. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v29i4p22.