Perhaps you should try some spelling variations:
"supply chains irrigation systems." » "supply change irrigation systems.", "supply canal irrigation systems.", "supply basin irrigation systems.", "supply chain irrigation systems.", "supply chains irrigation system."
"support low international aid." » "support law international aid.", "support how international aid.", "support new international aid.", "support low international bank.", "support low international _.", "support low international banks.", "support from international aid.", "support tool international aid."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply chains irrigation systems.") OR ("support low international aid."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"supply chains irrigation systems.\") OR (\"support low international aid.\"))*".
• Removing quotes may allow a broader search: (( supply chains irrigation systems. ) OR ( support low international aid. ))*.