Poluyanov, L. V.  Gonzalez, Miguel  Aguilar, Antonio, Jr. <br/><br/>
Group Properties of the Acoustic Differential Equation  Separation of Variables, Exact Solution 

 -  Taylor & Francis, Limited  1995. 
 - 165 
<br/><br/><label>ISBN: </label>0203211715 
<br/><br/><label>Dewey Class. No.: </label>515.35  /