Perhaps you should try some spelling variations:
importing countries » exporting countries, importing country
irrigation schemes » irrigation scheme, irrigation systems
shadow importing » sharing importing, shadow exploring
trip irrigation » drip irrigation, crop irrigation, grain irrigation
supply trip » supply tariff, supply trade

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

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