Ésik, Zoltán. “On the Weak Equivalence of Elgot’s Flow-Chart Schemata”. Acta Cybernetica 7, no. 2 (January 1, 1985): 146-154. Accessed April 19, 2024. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3283.