Perhaps you should try some spelling variations:
"process control statisticals methods." » "process control estadistica methods.", "process control estadistico methods.", "process control statisticss methods.", "process control estadisticass methods."
"procesal control statistical methods." » "social control statistical methods.", "proceso contra statistical methods.", "proces contre statistical methods.", "procesal control statistics methods.", "procesal control estadisticas methods."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("procesal control statistical methods.") or ("process control statisticals methods."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("procesal control statistical methods.") OR ("process control statisticals methods.")).
• Removing quotes may allow a broader search: (( procesal control statistical methods. ) or ( process control statisticals methods. )).
• Adding a wildcard symbol may retrieve word variants: (("procesal control statistical methods.") or ("process control statisticals methods."))*.