Perhaps you should try some spelling variations:
"process control statistics methods." » "process control estadistico methods.", "process control estadistica methods.", "process century statistics methods.", "process control statistical methods.", "process control statistics methodology.", "procesos control statistics methods.", "procesal control statistics methods."
"proceso control statistical factor." » "proceso control estadistico factor.", "proceso control statistical data.", "proceso contra statistical factor.", "proceso contralos statistical factor.", "proces contre statistical factor."

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

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