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