P . Berthold <br/><br/>
Birds Migration :  A general Survey 
Berthold  Peter 
 - Oxford  Oxford Univ . Press  1993 
 - x ,239p.: ill  hbk 
<br/><br/><label>ISBN: </label>0198546920 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Birds  -Migration