1. Krist FJ , Jr Sapio FJ Tkacz BM Mapping risk from forest insects and diseases 115 2007
2. Western forest insects /
3. Gibson K Kegley S Bentz B Mountain pine beetle. For. Insect Dis. Leafl. 2 12 2009
4. Forest Insect and Disease Conditions in the United States-2006. 2006 http://www.fs.fed.us/foresthealth/technology/pdfs/ConditionsReport_06_final.pdf