https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 The principle of inclusion-exclusion and möbius function as counting techniques in finite fuzzy subsets https://commons.ru.ac.za/vital/access/manager/Repository/vital:5413 Wed 12 May 2021 18:50:48 SAST ]]> Finite fuzzy sets, keychains and their applications https://commons.ru.ac.za/vital/access/manager/Repository/vital:5406 Thu 13 May 2021 06:49:38 SAST ]]>