Rezaei, Akbar, Hee Sik Kim, and Arsham Borumand Saeid. “Independence Concepts for Groupoids”. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica 22 (July 18, 2023): 87–98. Accessed November 24, 2024. https://studmath.uken.krakow.pl/article/view/10432.