Perhaps you should try some spelling variations:
"smart skills surveys." » "smart soil surveys."
"smart policy surveys." » "smart policy series.", "smart point surveys.", "smart topic surveys.", "summary policy surveys.", "market policy surveys.", "draft policy surveys."
"import policy surveys." » "import policy series.", "import point surveys.", "import topic surveys.", "important policy surveys.", "import price surveys."
"math skills series." » "motor skills series."

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: (((((("smart skills series.") OR ("math skills series."))) OR ((("smart skills surveys.") OR ((("smart policy surveys.") OR ("import policy surveys."))))))) OR ("soft skills survey."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"smart skills series.\") or (\"math skills series.\"))) or (((\"smart skills surveys.\") or (((\"smart policy surveys.\") OR (\"import policy surveys.\"))))))) or (\"soft skills survey.\"))~".
• Removing quotes may allow a broader search: (((((( smart skills series. ) or ( math skills series. ))) or ((( smart skills surveys. ) or ((( smart policy surveys. ) OR ( import policy surveys. ))))))) or ( soft skills survey. ))~.
• Adding a wildcard symbol may retrieve word variants: (((((("smart skills series.") or ("math skills series."))) or ((("smart skills surveys.") or ((("smart policy surveys.") OR ("import policy surveys."))))))) or ("soft skills survey."))*.