Perhaps you should try some spelling variations:
"particle acceleration" » "particle accelerators"
"particle accelerator" » "particle accelerators"
"partially correlated" » "spatially correlated", "serially correlated", "partially oriented"
"partially connected" » "impartially collected", "mutually connected"

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: (("particle accelerator") OR ((("particle acceleration") OR ((("partially correlated") OR ("partially connected")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"particle accelerator\") or (((\"particle acceleration\") or (((\"partially correlated\") OR (\"partially connected\"))))))".
• Removing quotes may allow a broader search: (( particle accelerator ) or ((( particle acceleration ) or ((( partially correlated ) OR ( partially connected )))))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((("particle acceleration") or ((("partially correlated") OR ("partially connected"))))))*.