Campbell, Robert W. <br/><br/>
Population dynamics of the major North American needle-eating budworms 
/ by Robert W. Campbell 
 - Portland :  USDA Forest Service,   1993. 
 - 222 p. ;  28 cm. 
<br/><br/> Research Paper PNW-RP-463, April 1993. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Insect populations--North America; Budworm populations--North America.
<br/><br/><label>Dewey Class. No.: </label>595.1 CAM  / 613