Perhaps you should try some spelling variations:
"global circulation issues" » "general circulation issues", "cerebral circulation issues", "global circulation issued", "global simulation issues", "global coagulation issues"
"global regulation issues" » "global regulatory issues", "global education issues", "global evaluation issues"

Try widening your search to All Fields.

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"global regulation issues\") OR (\"global circulation issues\"))".
• Removing quotes may allow a broader search: (( global regulation issues ) OR ( global circulation issues )).
• Adding a wildcard symbol may retrieve word variants: (("global regulation issues") OR ("global circulation issues"))*.