Freethy, Ron. <br/><br/>
How birds work :  a guide to bird biology / 
Ron Freethy. 
 - Poole :  Blandford,  1982. 
 - 232 p. , 8 p of plates :  ill. (some col.) maps ;  25 cm. 
<br/><br/>Bibliography : p214-227. - Includes index. 
<br/><br/><label>ISBN: </label>0713711566 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Birds--Physiology.