Perhaps you should try some spelling variations:
"procesos contables statistical methods." » "procesos control statistical methods.", "procesos sociales statistical methods.", "procesos penales statistical methods."
"process control statistics methods." » "process control statistical methods.", "process control estadistico methods.", "process control estadistica methods.", "process control statistics methodology.", "proceso control statistics methods.", "procesal control statistics 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 statistics methods.") OR ("procesos contables statistical methods."))~.
• Removing quotes may allow a broader search: (( process control statistics methods. ) or ( procesos contables statistical methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("process control statistics methods.") or ("procesos contables statistical methods."))*.