Encyclopedia of Mathematics and its applications <br/><br/>
Functional equations in several variables with applications to mathematics, information theory and to the natural and social sciences  / 

 - Cambridge:  Cambridge University Press,  1989 
 - xiii, 462p. Index, Bibl. 
 - Encyclopedia of Mathematics and its applications   V. 31 .
<br/><br/><label>Dewey Class. No.: </label>510.3  / En56.31