Perhaps you should try some spelling variations:
"scope research theories" » "scope research themes", "scope research topics", "scope research three", "europe research theories"
"scope research studies" » "scope research study", "europe research studies"
"scope research theory" » "scope research through", "europe research theory"

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: (("scope research studies") OR ((("scope research theories") OR ("scope research theory")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"scope research studies\") or (((\"scope research theories\") OR (\"scope research theory\"))))".
• Removing quotes may allow a broader search: (( scope research studies ) or ((( scope research theories ) OR ( scope research theory )))).
• Adding a wildcard symbol may retrieve word variants: (("scope research studies") or ((("scope research theories") OR ("scope research theory"))))*.