Copson, E.T.. <br/><br/>
Partial Differential Equations /  

 - 1st ed /  
 - London N.W.1 :   Cambridge University Press. 
 - p.280 :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics
<br/><br/><label>Dewey Class. No.: </label>B333  / L5