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

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

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