Fülöp, Zoltán, and Sándor Vágvölgyi. “Minimization of Deterministic Top-down Tree Automata”. Acta Cybernetica 23, no. 1 (January 1, 2017): 379–401. Accessed April 3, 2025. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3931.