OPEN Univeristy of SRi Lanka <br/><br/>
Foundation science level 2-physics orioertues if nmatter PSF 2602, block 4 

 - Nugegoda  The Open Unvieristy of Sri Lanka  1986 
 - 117 p. 
<br/><br/><label>ISBN: </label>139470 
<br/><br/><label>Dewey Class. No.: </label>539  / OPE