Perhaps you should try some spelling variations:
"global environmental governance system." » "global environment governance system.", "legal environment governance system.", "global environmental governance issues."
"Global environmental performance series." » "Global environmental performance metrics.", "Global environmental performance reviews.", "Global environmental performance review."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("Global environmental performance series.") OR ("global environmental governance system."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"Global environmental performance series.\") OR (\"global environmental governance system.\"))".
• Removing quotes may allow a broader search: (( Global environmental performance series. ) OR ( global environmental governance system. )).
• Adding a wildcard symbol may retrieve word variants: (("Global environmental performance series.") OR ("global environmental governance system."))*.