Barr A S <br/><br/>
Supervision : Democratic leadership in the improvement of learning 

 - 2nd 
 - New York, USA  Appleton - Century - Crofts  1938 
 - 879p. 
<br/><br/><label>Source: </label>Textual 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Teaching