http://www.ltu.acad.bg/

http://liternet.bg/

http://www.loc.gov/

http://www.metla.fi/info/vlib/Forestry/

http://forestry.lib.umn.edu/

http://www.library.utoronto.ca/earth/forestry.htm

http://www.library.yale.edu/hours/forestry.html

http://www.menominee.edu/library/Forestry.html