Perhaps you should try some spelling variations:
"supply curve irrigation schemes." » "supply curve irrigation scheme.", "supply curve irrigation systems.", "supply surge irrigation schemes.", "supply large irrigation schemes.", "supply crop irrigation schemes."
"supply covid testing services." » "supply covid existing services.", "supply covid lending services.", "supply covid training services.", "supply food testing services.", "supply load testing services.", "supply board testing services.", "supply cold testing services.", "supply soviet testing services.", "supply chain testing services."

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply covid testing services.") OR ("supply curve irrigation schemes."))~.
• Removing quotes may allow a broader search: (( supply covid testing services. ) or ( supply curve irrigation schemes. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply covid testing services.") or ("supply curve irrigation schemes."))*.