Calculus of several variables 
Lang, Serge, 
 - 3rd ed. 
 - New York :  Springer-Verlag,  1987 
 - xii, 503, [95] p. :  ill. ;  25 cm. 
 - Undergraduate texts in mathematics .
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0387964053 :