OPEN University of Sri Lanka <br/><br/>
Course of study leading to the degree of bachelor of science level 5 PSU 3122-po 

 - Nugegoda  The Open University of Sri Lanka  1991 
 - 44 p. 
<br/><br/><label>ISBN: </label>123731 
<br/><br/><label>Dewey Class. No.: </label>547.84  / OPE