Perhaps you should try some spelling variations:
integration efforts » international efforts, conservation efforts
grid integration » trade integration, _ integration, data integration
net migration » north migration, _ migration, return migration
support grid » support agri, support grant, support group
a migration » _ migration, _ emigration, _ immigration

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( supply ((net migration) OR (a migration)) policy. ) or ( support grid integration efforts. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply ((net migration) OR (a migration)) policy. ) OR ( support grid integration efforts. ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( supply ((net migration) OR (a migration)) policy. ) or ( support grid integration efforts. ))*".