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