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 statistics methodology.", "procesos control statistics methods.", "procesal control statistics methods."
"proceso control statistical methods." » "proceso contra statistical methods.", "proceso contralos statistical methods.", "proces contre statistical methods.", "proceso control estadisticas methods."

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