Leighton, Walter. <br/><br/>
Introduction to the Theory of Differential Equations /  

 - 1st ed /  
 - New York :   McGraw-Hill Book Company Inc. ,   1963 
 - p.174,vii :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics 
<br/><br/><label>Dewey Class. No.: </label>B333  / J2