http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Technological developments in aerial spraying
Combined Forest Pest Research and Development Program (U.S.)
1 online resource (15 pages) : illustrations (some color), charts
Aerial spraying and dusting in agriculture
Agriculture handbook (United States. Department of Agriculture) ; no. 535