Stephen, W. P. <br/><br/>
The biology and external morphology of bees  : with a synopsis of the genera of Northwestern America 

 - Corvallis, Ore. :  Agricultural Experimental Station,  1969 
 - 140 p.  : ilus. 
<br/><br/><label>LCCN: </label>57905 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Abejas--Anatomía y fisiología.
<br/><br/><label>Dewey Class. No.: </label>595.799  / S8