Perhaps you should try some spelling variations:
"yale agrarian studies." » "yale migration studies.", "yale asian studies.", "yale american studies.", "male agrarian studies.", "sale agrarian studies."
"enabling urban studies." » "enhancing urban studies.", "enabling rural studies."
"enable urban studies." » "viable urban studies.", "enhance urban studies.", "livable urban studies."

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: (("yale agrarian studies.") OR ((("enable urban studies.") OR ("enabling urban studies."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"yale agrarian studies.\") or (((\"enable urban studies.\") OR (\"enabling urban studies.\"))))~".
• Removing quotes may allow a broader search: (( yale agrarian studies. ) or ((( enable urban studies. ) OR ( enabling urban studies. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("yale agrarian studies.") or ((("enable urban studies.") OR ("enabling urban studies."))))*.