Chalenging problems in plant health / 
edited by Thor Kommedahl and Paul H. Williams 
 - Minnesota, U.S. :  The American Phytopathological Society,  1983 
 - 538 p. ;  24 cm. 
<br/><br/><label>ISBN: </label>0890540578 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plant health