Columbia subject headings:
Farmers--Diseases--United States.
Pesticides--Toxicology--United States.
Spraying and dusting residues in agriculture--Toxicology--United States.
Harvard subject headings:
Farmers--Diseases--United States.
Pesticides--Toxicology--United States.
Spraying and dusting residues in agriculture--Toxicology--United States.
Princeton subject headings:
Farmers--Diseases--United States.
Pesticides--Toxicology--United States.
Spraying and dusting residues in agriculture--Toxicology--United States.