Ujvári, Miklós. “New Descriptions of the Lovász Number, and the Weak Sandwich Theorem”. Acta Cybernetica 20, no. 4 (January 1, 2012): 499-513. Accessed May 18, 2022. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3824.