Perhaps you should try some spelling variations:
"american studies theories" » "american studies theory", "american des theories", "american studies three"
"american studies species" » "american studies special", "american studies studies", "american species species"
"american studies series" » "american studies services", "american studies studies", "american studies service"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("american studies series") OR ("american studies theories"))) OR ("american studies species")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"american studies series\") OR (\"american studies theories\"))) or (\"american studies species\"))".
• Removing quotes may allow a broader search: (((( american studies series ) OR ( american studies theories ))) or ( american studies species )).
• Adding a wildcard symbol may retrieve word variants: (((("american studies series") OR ("american studies theories"))) or ("american studies species"))*.