Perhaps you should try some spelling variations:
"process control estadistica datos." » "process control estadistico datos.", "process economia estadistica datos.", "process control estadisticas datos.", "process control estadistica casos.", "process control estadistica usos."
"procesal control statistical methods." » "social control statistical methods.", "proceso contra statistical methods.", "proces contre statistical methods.", "procesal control statistics methods.", "procesal control estadisticas methods."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("procesal control statistical methods.") or ("process control estadistica datos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("procesal control statistical methods.") OR ("process control estadistica datos.")).
• Removing quotes may allow a broader search: (( procesal control statistical methods. ) or ( process control estadistica datos. )).
• Adding a wildcard symbol may retrieve word variants: (("procesal control statistical methods.") or ("process control estadistica datos."))*.