Research activities in fuzzy set theory and applications at the computation science and artificial intelligence group in Public University of Navarre, Pamplona, Spain. - Humberto Bustince; León González (Fuzzy Sets Syst., 1996)

Level-based extension of relations. - León González; Ángel Marín (Fuzzy Sets Syst., 1996)

Algorithmic estimate for aggregated powerset relations. - León González; Ángel Marín (Fuzzy Sets Syst., 1997)

Weak properties and aggregated extension of fuzzy relations. - León González; Ángel Marín (Fuzzy Sets Syst., 1997)

A note on the infinitary action of triangular norms and conorms. - León González (Fuzzy Sets Syst., 1999)