Grannell, Mike J, and Thomas A McCourt. “Doubly Even Orientable Closed 2-Cell Embeddings of the Complete Graph”. The Electronic Journal of Combinatorics 21, no. 1 (February 7, 2014): P1.22. Accessed March 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v21i1p22.