Oppenheim, Alan V. <br/><br/>
Signals and systems. 

 - London :  Prentice-Hall,  1983. 
 - xix,796p. 
 - Prentice-Hall signal processing series .
<br/><br/><label>ISBN: </label>0138097313 
<br/><br/><label>Source: </label> Textual