Perhaps you should try some spelling variations:
"process control statistical methodology." » "process control statistics methodology.", "proceso control statistical methodology.", "procesal control statistical methodology."
"procesos previos statistical methods." » "procesos problems statistical methods.", "procesos nuevos statistical methods.", "procesos creativos statistical methods.", "procesos graficos statistical methods."

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: (("process control statistical methodology.") OR ("procesos previos statistical methods."))~.
• Removing quotes may allow a broader search: (( process control statistical methodology. ) or ( procesos previos statistical methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("process control statistical methodology.") or ("procesos previos statistical methods."))*.