United States. DEPARTMENT OF AGRICULTURE. ECONOMIC RESEARCH SERVICE. WORLDWIDE USE OF AIRPHOTOS IN AGRICULTURE.
Chicago-viite (17. p.)United States. DEPARTMENT OF AGRICULTURE. ECONOMIC RESEARCH SERVICE. WORLDWIDE USE OF AIRPHOTOS IN AGRICULTURE. U.S.G.P., 1967. (AGRICULTURE HANDBOOK NO. 344).
MLA-viite (8. p.)United States. DEPARTMENT OF AGRICULTURE. ECONOMIC RESEARCH SERVICE. WORLDWIDE USE OF AIRPHOTOS IN AGRICULTURE.
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