Perhaps you should try some spelling variations:
"process control estadisticas datos." » "process control estadistica datos.", "process control estadistico datos.", "process economia estadisticas datos.", "process control estadistica casos.", "process control estadisticas metodos.", "process control estadisticas de."
"procesal control statistical methods." » "social control statistical methods.", "proceso contra statistical methods.", "proces contre statistical methods.", "procesal 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: (("procesal control statistical methods.") or ("process control estadisticas datos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("procesal control statistical methods.") OR ("process control estadisticas datos."))*.
• Removing quotes may allow a broader search: (( procesal control statistical methods. ) or ( process control estadisticas datos. ))*.