The new understanding why / 
Thomas I. Dowling and [et al...] 
 - Teachers ed. 
 - Philadelphia :  The John C. Winston Company,  1957. 
 - 412 p. :  ills. ;  24 cm. 
<br/><br/>   
<br/><br/><label>Subjects--Topical Terms: </label><br/>Understanding
<br/><br/><label>Dewey Class. No.: </label>507 / D756m