OPEN University of Sri Lanka <br/><br/>
A course of study leading to the degree of bachelor of science level 3, CHU 1221 

 - Nugegoda  The Open University of Sri Lanka  1995 
 - 99 p. 
<br/><br/><label>ISBN: </label>123642 
<br/><br/><label>Dewey Class. No.: </label>540  / OPE