Perhaps you should try some spelling variations:
"math skills surveys." » "math skills survey.", "math soil surveys.", "motor skills surveys."
"small schools serve." » "small school service."
"math site surveys." » "math firm surveys."
"math school surveys." » "map school surveys.", "small school surveys.", "smart school surveys."
"math school survey." » "map school survey.", "small school survey.", "smart school survey."
"math social surveys." » "cash social surveys.", "data social surveys.", "health social surveys."

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: (("math skills surveys.") OR ((((((((("math school surveys.") OR ("math school survey."))) OR ("math social surveys."))) OR ("math site surveys."))) OR ((("small schools survey.") OR ("small schools serve."))))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"math skills surveys.\") or (((((((((\"math school surveys.\") OR (\"math school survey.\"))) or (\"math social surveys.\"))) or (\"math site surveys.\"))) or (((\"small schools survey.\") or (\"small schools serve.\"))))))~".
• Removing quotes may allow a broader search: (( math skills surveys. ) or ((((((((( math school surveys. ) OR ( math school survey. ))) or ( math social surveys. ))) or ( math site surveys. ))) or ((( small schools survey. ) or ( small schools serve. ))))))~.
• Adding a wildcard symbol may retrieve word variants: (("math skills surveys.") or ((((((((("math school surveys.") OR ("math school survey."))) or ("math social surveys."))) or ("math site surveys."))) or ((("small schools survey.") or ("small schools serve."))))))*.