Lefschetz, Solomon. <br/><br/>
Differential equations :  geometric theory / 
by Solomon Lefschetz. 
 - 2nd ed. 
 - New York, N.Y. :  Dover Publications,  1977. 
 - x, 390 p. 
<br/><br/><label>ISBN: </label>0486634639 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations.