Compendium of apple and pear diseases 
edited by A.L. Jones, H.S. Aldwinckle 
 - St. Paul, Minnesota  APS Press  cop. 1990 
 - VI, 100 p., [22] p. de lám.  il.  30 cm 
<br/><br/><label>ISBN: </label>0890541094 
<br/><br/><label>Subjects--Index Terms: </label>Enfermedades de las plantas Pera Fitopatologia Manzana