Perhaps you should try some spelling variations:
"supply based immunization systems." » "supply based communication systems.", "supply based immunization rates.", "supply based immunization costs.", "supply basic immunization systems.", "supply mass immunization systems.", "supply measles immunization systems.", "supply case immunization systems.", "supply water immunization systems.", "survey based immunization systems."
"supply grid irrigation schemes." » "supply grid irrigation scheme.", "supply grid irrigation systems.", "supply drip irrigation schemes.", "supply syria irrigation schemes.", "supply crop irrigation schemes.", "supply crowd irrigation schemes.", "support grid irrigation schemes."

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 grid irrigation schemes.") OR ("supply based immunization systems."))~.
• Removing quotes may allow a broader search: (( supply grid irrigation schemes. ) or ( supply based immunization systems. ))~.
• Adding a wildcard symbol may retrieve word variants: (("supply grid irrigation schemes.") or ("supply based immunization systems."))*.