Circuits, Helena. <br/><br/>
Biology / 
Helena Circuits. 
 - 3rd ed. 
 - New York :  Worth,  c 1979. 
 - xxvii,127 p. :  ill. ;  26 cm. 
<br/><br/> Includes index. 
<br/><br/>339  339 
<br/><br/><label>ISBN: </label>0-8791-100-9 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Boilogy.
<br/><br/><label>Dewey Class. No.: </label>574 / C941b