Perhaps you should try some spelling variations:
"proces contreles statistical datos." » "proces contreles statistical data.", "proces contreles estadisticas datos.", "proces contreles statistics data.", "proceso contralos statistical datos.", "proces contre statistical datos.", "procesos contables statistical datos."
"process control statistical methods." » "procesos control statistical methods.", "proceso control statistical methods.", "procesal control statistical 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: (("process control statistical methods.") OR ("proces contreles statistical datos."))~.
• Removing quotes may allow a broader search: (( process control statistical methods. ) or ( proces contreles statistical datos. ))~.
• Adding a wildcard symbol may retrieve word variants: (("process control statistical methods.") or ("proces contreles statistical datos."))*.