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

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