Blough, Glenn Orlando. <br/><br/>
Elementary school science and how to teach it / 
Glenn Orlando Blough, Julius Schwartz and Albert J. Huggett. 
 - Rev ed. 
 - USA :  Holt-Dryden,  c 1958. 
 - xvi, 608 p. :  ill. ;  26 cm. 
<br/><br/> Includes index. 
<br/><br/>Bibliography : p. 564-591. 
<br/><br/>341  341 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Technology --health.--science 
<br/><br/><label>Dewey Class. No.: </label>372.3 / B623c