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

Try widening your search to All Fields.

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