Perhaps you should try some spelling variations:
"particle acceleration" » "particle accelerators"
"partially accelerated" » "partially correlated", "partially integrated", "naturally accelerate"
"particle accelerator" » "particle accelerators"
"particle acceleraton" » "particles acceleration", "particle accelerations", "pareticle acceleration"
"practice accelerate" » "practice accelerated", "practices accelerate", "practices accelerating"

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 ((("practice accelerate") OR ((((("particle acceleration") OR ("partially accelerated"))) OR ("particle acceleraton")))))).
• Removing quotes may allow a broader search: (( particle accelerator ) or ((( practice accelerate ) or ((((( particle acceleration ) or ( partially accelerated ))) or ( particle acceleraton )))))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((("practice accelerate") or ((((("particle acceleration") or ("partially accelerated"))) or ("particle acceleraton"))))))*.