Perhaps you should try some spelling variations:
"oponente of U.S. involvement in the Vietnam War" » "openente of U.S. involvement in the Vietnam War", "ponente of U.S. involvement in the Vietnam War", "componente of U.S. involvement in the Vietnam War"
"oponentes of U.S. involvement in the Vietnam War" » "openentes of U.S. involvement in the Vietnam War", "ponentes of U.S. involvement in the Vietnam War", "componentes of U.S. involvement in the Vietnam War", "exponentes of U.S. involvement in the Vietnam War"
"component of U.S. involvement in the Vietnam War" » "componente of U.S. involvement in the Vietnam War", "components of U.S. involvement in the Vietnam War", "componen of U.S. involvement in the Vietnam War"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("oponente of U.S. involvement in the Vietnam War") OR ("oponentes of U.S. involvement in the Vietnam War"))) OR ("component of U.S. involvement in the Vietnam War"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"oponente of U.S. involvement in the Vietnam War\") OR (\"oponentes of U.S. involvement in the Vietnam War\"))) OR (\"component of U.S. involvement in the Vietnam War\"))".
• Removing quotes may allow a broader search: (((( oponente of U.S. involvement in the Vietnam War ) OR ( oponentes of U.S. involvement in the Vietnam War ))) OR ( component of U.S. involvement in the Vietnam War )).
• Adding a wildcard symbol may retrieve word variants: (((("oponente of U.S. involvement in the Vietnam War") OR ("oponentes of U.S. involvement in the Vietnam War"))) OR ("component of U.S. involvement in the Vietnam War"))*.