Columbia subject headings:
Harvard subject headings:
Chemical warfare.
Gases, Asphyxiating and poisonous--War use.
Herbicides--Toxicology.
Herbicides--War use.
Pesticides--Environmental aspects
Princeton subject headings:
Chemical warfare.
Gases, Asphyxiating and poisonous--War use.
Herbicides--Toxicology.
Herbicides--War use.
Pesticides--Environmental aspects.