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Symmetries and Integrability of Difference Equations 

 - Cambridge  Cambridge University Press  1999 
 - xvi,424p.  28 cm. PB 
 - London Mathematical Society Lecture Note Series .
<br/><br/><label>ISBN: </label>9780521596992 
<br/><br/><label>Dewey Class. No.: </label>515.35  / SYM