Perhaps you should try some spelling variations:
"particle accelerating" » "particle accelerations", "particle acceleration", "particles acceleration"
"particle accelerator" » "particle acceleration"
"particle accelerators" » "particle accelerations", "particle acceleration"
"particle accelerated" » "particles accelerated", "particle acceleration", "partially accelerated"
"naturally accelerate" » "naturally regenerated", "partially accelerated"
"particle acceleraton" » "particle acceleration", "particles acceleration", "particle accelerations"

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 accelerators") OR ("particle accelerating"))) OR ((((("particle accelerated") OR ("naturally accelerate"))) OR ("particle acceleraton")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"particle accelerator\") or (((((\"particle accelerators\") OR (\"particle accelerating\"))) or (((((\"particle accelerated\") or (\"naturally accelerate\"))) or (\"particle acceleraton\"))))))".
• Removing quotes may allow a broader search: (( particle accelerator ) or ((((( particle accelerators ) OR ( particle accelerating ))) or ((((( particle accelerated ) or ( naturally accelerate ))) or ( particle acceleraton )))))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((((("particle accelerators") OR ("particle accelerating"))) or ((((("particle accelerated") or ("naturally accelerate"))) or ("particle acceleraton"))))))*.