Riečanová, Zdenka, and Michal Zajac. “Intervals in Generalized Effect Algebras and Their Sub-Generalized Effect Algebras”. Acta Polytechnica 53, no. 3 (January 3, 2013). Accessed April 24, 2024. https://ojs.cvut.cz/ojs/index.php/ap/article/view/1817.