Kaufmann, A. <br/><br/>
Introduction to the theory of fuzzy subsets  / 

 - New York:  Academic Press,  1975 
 - xvi, 416p. 
<br/><br/> "Translated by D. L. Swanson" 
<br/><br/><label>Dewey Class. No.: </label>511.3  / K21.IT