Perhaps you should try some spelling variations:
"process control estadisticas methods." » "process control estadistica methods.", "process control estadistico methods.", "process control statistical methods.", "process control estadisticas metodos.", "process control estadisticas datos.", "procesos control estadisticas methods.", "procesal control estadisticas methods."
"proceso control statistics methods." » "proceso control statistical methods.", "proceso control estadistico methods.", "proceso control estadistica methods.", "proceso control statistics methodology.", "proceso contra statistics methods.", "proceso contralos statistics methods.", "proces contre 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 estadisticas methods.") or ("proceso control statistics methods."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("process control estadisticas methods.") OR ("proceso control statistics methods.")).
• Removing quotes may allow a broader search: (( process control estadisticas methods. ) or ( proceso control statistics methods. )).
• Adding a wildcard symbol may retrieve word variants: (("process control estadisticas methods.") or ("proceso control statistics methods."))*.