Hobbs, Albert Hoyt <br/><br/>
Differentials in internal migration / 
Albert Hoyt Hobbs 
 - Philadelphia :  University of Pennsylvania,  1942 
 - xi, 122 p. :  ill. ;  20 cm. 
<br/><br/>Thesis (Ph. D.) - University of Pennsylvania, 1942 
<br/><br/>Bibliography: p. 119-122 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Migration, Internal