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