Perhaps you should try some spelling variations:
"process control estadistico methods." » "process control statistical methods.", "process control estadisticas metodos."
"procesal control statistics methods." » "procesal control statistical methods.", "procesal control estadistica methods.", "procesal century statistics methods.", "procesal control statistics methodology.", "social control statistics methods.", "proceso contra statistics methods.", "proces contre statistics 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: (("procesal control statistics methods.") OR ("process control estadistico methods."))~.
• Removing quotes may allow a broader search: (( procesal control statistics methods. ) or ( process control estadistico methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("procesal control statistics methods.") or ("process control estadistico methods."))*.