Fundamentals of ecology / 
Odum Eugene P. 
 - 3rd ed. 
 - Philadelphia :  Saunders College Publishing ,  1971. 
 - xiv,574 p.: 
<br/><br/><label>ISBN: </label>0721669417 
<br/><br/><label>LC Class. No.: </label>QH541  / .O32 1971