Perhaps you should try some spelling variations:
"pparticle acceleration" » "particle acceleration", "particles acceleration", "particle accelerations"
"particle accelerator" » "particle accelerators", "particle acceleration", "pparticle accelerators", "pparticle acceleraton", "pparticle acceleration"
"article accelerator" » "particle accelerators", "particle acceleraton", "particle acceleration"

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