James D. Crutchfield

Nitrate-Nitrogen and Phosphate-Phosphorus in Seven Kentucky Streams Draining Small Agricultural Watersheds: Eighteen Years Later

G. W. Thomas, Grant W. Thomas, G. R. Haszler, 1992 .

Nitrate-Nitrogen and Phosphorus Contents of Streams Draining Small Agricultural Watersheds in Kentucky 1

G. W. Thomas, Grant W. Thomas, James D. Crutchfield, 1974 .