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