Two studies of Puerto Rican labor mobility.  Volume I  Labor mobility among social security covered workers in the Puerto Rican labor force. 

 - [San Juan?]  Commonwealth of Puerto Rico, Office of the Governor, Planning Board, Area of Economic and Social Planning, Bureau of Social Planning  1974. 
 - 207 p.  ill., map  28 cm. 
<br/><br/>Bibliography: p. 206-207. 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Puerto Rico--Labor mobility.