Ching-Chau Yu <br/><br/>
Nonlinear Singularities and Analytic-Hypoellipticity. 
Ching-Chau Yu 
 - Providence  Amer. Math. Soc.  1998 
 - 92 p. 
<br/><br/> Memoirs of the Amer. Math. Soc., Vol. 134, N 636 
<br/><br/><label>Dewey Class. No.: </label>MAMS