Helgason, Sigurdur <br/><br/>
Groups and geometric analysis : Integral geometry, invariant differential operators and spherical functions 
by Sigurdur Helgason 
 - USA  American Mathematical Society  1984 
 - xxii, 667p 
 - Mathematical surveys and monographs Vol.83   .
<br/><br/><label>ISBN: </label>9780821826737 
<br/><br/><label>Dewey Class. No.: </label>512.55  / N842;1