P. F. Sand

Pesticide residue levels in soils, FY 1969--National Soils Monitoring Program.

G. Wiersma, H. Tai, P. F. Sand, 1972, Pesticides monitoring journal.

Pesticide residue levels in soils and crops, FY-70--national soils monitoring program (II).

G. Wiersma, A. Carey, H. Tai, 1974, Pesticides monitoring journal.

Pesticide residues in soil from eight cities--1969.

G. Wiersma, H. Tai, P. F. Sand, 1972, Pesticides monitoring journal.

Witchweed research and control in the United States

R. Westbrooks, R. Eplee, P. F. Sand, 1990 .

Advances in Witchweed Control

P. F. Sand, W. C. Shaw, D. Shepherd, 1962 .