Leff, Gordon <br/><br/>
History and social theory / 
Gordon Leff 
 - London :  Merlin Press,  1969 
 - 240 p. ;  23 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>History--Methodology<br/>History--Research