Demetrovics, János, and Vu Duc Thi. “Normal Forms and Minimal Keys in the Relational Datamodel”. Acta Cybernetica 11, no. 3 (January 1, 1994): 205–215. Accessed January 26, 2026. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3429.