Thomas, Dorothy Swaine <br/><br/>
Research memorandum on migration differentials / 
by Dorothy Swaine Thomas ; with contributions by Rudolf Heberle ... [et al.] 
 - New York :  Social Science Research Council,  1938 
 - 423 p. :  ill. ;  23 cm. 
 - Bulletin / Social Science Research Council ;  43 .
 - Bulletin (Social Science Research Council) ;  43 .