National science education standards / 
National Reaserch Council. 
 - 9th printing 
 - Washington, D.C :  National Academy Press,  2003. 
 - 262 p. 
<br/><br/><label>ISBN: </label>0309053269 
<br/><br/><label>LCCN: </label>9545778 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science--Study and Teaching--Standards--United States