Perhaps you should try some spelling variations:
"supply channels irrigation scheme." » "supply change irrigation scheme.", "supply canal irrigation scheme.", "supply channels information scheme.", "supply channels irrigation systems.", "supply chains irrigation scheme."
"supply city sanitation systems." » "supply city irrigation systems.", "supply site sanitation systems.", "supply security sanitation systems.", "supply water sanitation systems.", "supply cote sanitation systems.", "supply costs sanitation systems.", "supply china sanitation systems."

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 channels irrigation scheme.") OR ("supply city sanitation systems."))~.
• Removing quotes may allow a broader search: (( supply channels irrigation scheme. ) or ( supply city sanitation systems. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply channels irrigation scheme.") or ("supply city sanitation systems."))*.