Perhaps you should try some spelling variations:
immigration efforts » integration efforts, immigration affects, immigration reform
irrigation schemes » irrigation scheme, irrigation systems
grain irrigation » gray irrigation, gravity irrigation, drip irrigation
mass immigration » mass migration, _ immigration
supply grain » supply chain, supply main, supply ukraine
export mass » export bases, export basis, export base

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

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