| Chemical warfare -- History. Matches 3 items |
| Chemical warfare -- History -- 20th century. Matches 1 item |
| Chemical warfare -- History -- To 1500. Matches 1 item |
| Chemical warfare -- Research -- United States -- History -- 20th century. Matches 1 item |
| Chemical warfare -- Soviet Union. Matches 1 item |
| Chemical warfare -- Technological innovations -- History. Matches 1 item |
| Chemical warfare -- United States. Matches 1 item |
| Chemical warfare -- United States -- History -- 20th century. Matches 1 item |
| Chemical weapons. Matches 1 item |
| Chemical weapons -- Congresses. Matches 1 item |