1. Progress toward improving aerial defoliation survey methods by using electronic imagers;Ahern;Photogramm. Eng. Remote Sens.,1991
2. Observation limits for aerial sketch-mapping southern pine beetle damage in the southern Appalachians;Aldrich;J. For.,1958
3. Damage assessment and integrated pest management of forest defoliators;Alfaro;For. Ecol. Manage.,1991
4. British National Space Centre (BNSC), 2002. New low cost UK earth observation instrument orbits the earth on a European satellite. URL (last accessed 29/11/2004): http://www.bnsc.gov.uk/default.aspx%3F;nid=3420%26;hl=chris.
5. The State of Canada's Forests 2001–2002,2002