The PC-SIG encyclopedia of shareware / 

 - 4th ed. 
 - Blue Ridge Summit, PA :  Windcrest,  c1991. 
 - 690 p. :  ill. ;  23 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0830626697 (pbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Shareware (Computer software)
<br/><br/><label>Dewey Class. No.: </label>005.365