Tanzania journal of science/ 
University of Dar es Salaam 
 - Dar es Salaam:  Facult of science,University of Dar es Salaam,  2006 
 - 111p. :  ill. 
<br/><br/><label>ISSN: </label>0856-1761 
<br/><br/><label>Dewey Class. No.: </label>EA.505 TAN