Perhaps you should try some spelling variations:
immigration policies » immigration policy, migration policy
integration schemes » integration schengen, irrigation schemes, integration regimes
gross immigration » gross emigration, mass immigration, from immigration
how integration » new integration, how interaction, die integration
supply gross » supply growth, supply costs, supply cost

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( supply how integration schemes. ) or ( supply gross immigration policies. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply how integration schemes. ) OR ( supply gross immigration policies. )).
• Adding a wildcard symbol may retrieve word variants: (( supply how integration schemes. ) or ( supply gross immigration policies. ))*.