Perhaps you should try some spelling variations:
"proceso control estadisticas metodos." » "proceso control estadistica metodos.", "proceso control estadistico metodos.", "proceso economia estadisticas metodos.", "proceso contra estadisticas metodos.", "proceso contralos estadisticas metodos.", "proces contre estadisticas metodos."
"process control statistical methods." » "procesos control statistical methods.", "procesal control statistical methods.", "process control statistics methods."

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