Brewer, Richard, <br/><br/>
Principles of ecology 
Richard Brewer. 
 - Philadelphia  Saunders College Publishing  1979. 
 - 299 pages :    illustration,    24cm. 
<br/><br/> p. 281-282. 
<br/><br/><label>ISBN: </label>0721619886 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology