Demetrovics, J., and Vu Duc Thi. “Some Observations on the Minimal Armstrong Relations for Normalised Relation Schemes”. Computing and Informatics 14, no. 5 (January 27, 2012): 455–467. Accessed November 8, 2024. http://147.213.75.17/ojs/index.php/cai/article/view/286.