Jelínek, Vít, and Martin Töpfer. “On Grounded L-Graphs and Their Relatives”. The Electronic Journal of Combinatorics 26, no. 3 (July 19, 2019): P3.17. Accessed March 28, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v26i3p17.