Young AP, Modgil S, Rodrigues O. Prioritised Default Logic as Rational Argumentation(PDF). Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2016). Retrieved 16 January 2025.
Brian A. Davey and Hilary Ann Priestley (1990). Introduction to Lattices and Order. Cambridge Mathematical Textbooks. Cambridge University Press. ISBN0-521-36766-2. LCCN89009753. Here: p. 100