Vrana, Ralph S. <br/><br/>
Junior high school science activities / 
by Ralph S. Vrana. 
 - West Nyack, New York :  Parker Publishing Company,  1969. 
 - x, 213 p. :  ill. ;  26 cm. 
<br/><br/>Bibliography : p. 205-208. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science--Study and teaching (Secondary).