Investigating the earth: Earth science curriculum project / 
s.n. 
 -  Houghton Mifflin Company, Boston,  1968 
 - p. ;  22 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sciences of earth & other worlds
<br/><br/><label>Dewey Class. No.: </label>550 INV