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