Stephen, Peter,  <br/><br/>
Simple statistics for library and information professionals 
Peter Stephen and Susan Hornby. 
 - 2nd edition. 
 - London;   Library Association,   1997. 
 - 229 pages:   illustrations;   22 cm. 
<br/><br/>pages 225-226 
<br/><br/><label>ISBN: </label>1856042200  RM122.26 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Statistics.<br/>Libraries.