Meduna, Alexander, and Martin Švec. “Reduction of Simple Semi-Conditional Grammars With Respect to the Number of Conditional Productions”. Acta Cybernetica 15, no. 3 (January 1, 2002): 353-360. Accessed April 26, 2024. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3584.