Armitage, P. & Berry, G. <br/><br/>
Statistical methods in medical research 

 - 2nd ed 
 - Blackwell Scientific publications, Oxford  1987 
 - xiii,559p 
<br/><br/><label>ISBN: </label>0-632-01501-2 
<br/><br/><label>Dewey Class. No.: </label>610.72 Arm/Ber