Perhaps you should try some spelling variations:
"support policy integration theories." » "support policy integration theorems.", "support policy integrationstheorie 2.", "support policy integration theory.", "support political integration theories.", "support policy international theories.", "support policy intervention theories.", "support policies integration theories.", "import policy integration theories."
"support worker irrigation schemes." » "support worker irrigation scheme.", "support worker irrigation systems.", "support border irrigation schemes.", "support water irrigation schemes.", "support holder irrigation schemes.", "support workers irrigation schemes.", "support biomarker irrigation schemes."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("support worker irrigation schemes.") or ("support policy integration theories."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support worker irrigation schemes.") OR ("support policy integration theories.")).
• Removing quotes may allow a broader search: (( support worker irrigation schemes. ) or ( support policy integration theories. )).
• Adding a wildcard symbol may retrieve word variants: (("support worker irrigation schemes.") or ("support policy integration theories."))*.