Zhi-fen, Zhang <br/><br/>
Qualitative theory of differential equations 

 - Providence  American Mathematical Society  1991 
 - xiv,464p, 22cm 
 - Translations of mathematical monographs .
<br/><br/><label>ISBN: </label>0821845519 
<br/><br/><label>Dewey Class. No.: </label>515.35,  / D, ant