Ayres, Leonard Porter,  1879-1946. <br/><br/>
Constant and variable occupations and their bearing on problems of vocational education. 

 - New York City,  Division of Education, Russell Sage Foundation  [1914] 
 - 11 p.  23 cm. 
 - [Russell Sage Foundation, New York.  Division of Education.  Pamphlets] E136 .
<br/><br/><label>LCCN: </label>e  14002061  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Vocational guidance.<br/>Occupations.
<br/><br/><label>LC Class. No.: </label>HF5381  / .A85