Witts, L. J. <br/><br/>
Medical surveys and clinical trials :   some methods and applications of group research in medicine 

 - 2a. ed 
 - London :   Oxford University Press,   1964. 
 - 367 p. ; 21 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Medicina
<br/><br/><label>Universal Decimal Class. No.: </label>61