Freethy, Ron. <br/><br/>
Secrets of bird life :  a guide to bird biology / 
Ron Freethy. 
 - Rev. ed. 
 - London :  Sterling Pub.,  1990. 
 - xi, 232 p. 
<br/><br/><label>ISBN: </label>0713721545 
<br/><br/><label>LCCN: </label>92014100     
<br/><br/><label>Subjects--Topical Terms: </label><br/>Birds--Physiology.