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