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