Perhaps you should try some spelling variations:
"social control estadistica methods." » "social control estadistico methods.", "social control statistical methods.", "social economia estadistica methods.", "social control estadisticas metodos.", "social control estadisticas medicas."
"process control statistics methods." » "process control statistical methods.", "process control estadistico methods.", "process century statistics methods.", "process control statistics methodology.", "procesos control statistics methods.", "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 ("social control estadistica methods."))~.
• Removing quotes may allow a broader search: (( process control statistics methods. ) or ( social control estadistica methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("process control statistics methods.") or ("social control estadistica methods."))*.