Petrovskii, I. G. <br/><br/>
Partial differential equations 
I. G. Petrovskii 
 - Philadelphia  W. B. Saunders  1967. 
 - 410 pages :    illastration ;    21 cm. 
 - Saunders mathematics books .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations, Partial