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 estadistico methods." » "process control statistical methods.", "process control estadisticas metodos.", "proceso control estadistico methods.", "procesal control estadistico 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 estadistico methods.") OR ("procesos contables statistical methods."))~.
• Removing quotes may allow a broader search: (( process control estadistico methods. ) or ( procesos contables statistical methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("process control estadistico methods.") or ("procesos contables statistical methods."))*.