Exterior differential systems / 
Robert L. Bryant ... [et al.]. 
 - New York :  Springer-Verlag,  c1991. 
 - vii, 475 p. 
 - Mathematical Sciences Research Institute publications ;  18 .
<br/><br/><label>ISBN: </label>3540974113 
<br/><br/><label>LCCN: </label>91065155     
<br/><br/><label>Subjects--Topical Terms: </label><br/>Exterior differential systems.<br/>Differential equations, Partial.