On a story inspired by IF-sets

Riečan, Beloslav, 1936-2018

On a story inspired by IF-sets / Beloslav Riečan

In New Developments in Fuzzy Sets, Intuitionistic Fuzzy Sets, Generalized Nets and Related Topics Atanassov, Krassimir. -- Warszaw : Systems Research Institute, Polish Academy of Sciences, 2012. -- ISBN ISBN 83-894-7540-5. -- S. 149-156