Perhaps you should try some spelling variations:
"fractionally integrated" » "fractional integral", "fractional integrals", "fractional integration"
"particle acceleration" » "particle accelerators"
"particle accelerator" » "particle accelerators"

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 ("fractionally integrated")))).
• Removing quotes may allow a broader search: (( particle accelerator ) or ((( particle acceleration ) or ( fractionally integrated )))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((("particle acceleration") or ("fractionally integrated"))))*.