Schaeffer, Gilles. “Bijective Census and Random Generation of Eulerian Planar Maps With Prescribed Vertex Degrees”. The Electronic Journal of Combinatorics 4, no. 1 (July 17, 1997): R20. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v4i1r20.