Fuzzy sets in psychology / edited by Tamás Zétényi.    Amsterdam : North-Holland ; New York : Sole distributors for the U.S.A. and Canada, Elsevier Science Pub. Co., 1988 . 1 online zdroj (xi, 470 stran)
http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&AN=239793