Konev, Boris, Roman Kontchakov, Michel Ludwig, Thomas Schneider, Frank Wolter, and Michael Zakharyaschev. “Conjunctive Query Inseparability of OWL 2 QL TBoxes”. Proceedings of the AAAI Conference on Artificial Intelligence 25, no. 1 (August 4, 2011): 221–226. Accessed May 7, 2026. https://ojs.aaai.org/index.php/AAAI/article/view/7846.