 | Airphoto use in resource management | (1) |
 |
 | Airphoto use in resource management : a survey of non-federal purchasers of Agricultural Stabilization and Conservation Service airphotos / by Orville E. Krause. Krause, Orville E. 1n Washington, D.C. : Economic Research Service, U.S. Dept. of Agriculture, 1969. | |
|