Heck, William Harry,  1879- <br/><br/>
A study of school recesses. 

 - [Charlottesville, Va.]  The University  [1917] 
 - 22 p.  23 cm. 
 - University of Virginia record.  Extension ser.,  vol. III, no. 1, September, 1917 .
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<br/><br/><label>LCCN: </label>e  18000176  
<br/><br/><label>LC Class. No.: </label>LB3033  / .H4