Subject
- Affiliation (Psychology) -- United States1
- Agricultural conservation -- Oregon -- Willamette River Valley -- Economic aspects1
- Agricultural conservation -- Oregon -- Willamette River Valley -- Evaluation1
- Agricultural credit -- United States1
- Agricultural pollution -- Oregon -- Willamette River Valley1
- Agricultural price supports -- United States2
- Agricultural subsidies -- Economic aspects -- United States1
- Agricultural subsidies -- United States1
- Agriculture -- Economic aspects1
- Agriculture -- Economic aspects -- Oregon1
- Agriculture -- Economic aspects -- United States4
- Agriculture -- Research -- Economic aspects -- United States1
- Agriculture and state -- Environmental aspects -- Oregon -- Willamette River Valley1
- Agriculture and state -- Oregon1
- Agriculture and state -- Tunisia -- Econometric models1
- Agriculture and state -- United States2
- Air -- Pollution -- Government policy -- Economic aspects -- United States1
- Airlines -- Economic aspects -- United States2
- Airlines -- Mergers -- Economic aspects -- United States1
- Airlines -- Mergers -- Government policy -- Economic aspects -- United States1