Schaefer, Douglas L. <br/><br/>
Programmed learning aid for basic facts on ecology and the social sc iences  /  
Douglas L. Schaefer. 
 - Homewood, Ill. :    Richard D. Irwin,    c1973. 
 - vi, 57 p. ;    26 cm. 
 - Programmed Learning Aid Series .
<br/><br/>  Includes index 
<br/><br/><label>ISBN: </label>0256014949 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Human ecology.<br/> Social ecology.
<br/><br/><label>Dewey Class. No.: </label>304.2