Perhaps you should try some spelling variations:
"proces contreles statistical datos." » "proces control statistical datos.", "proces contreles statistical data.", "proces contreles estadisticas datos.", "proces contreles statistical methods.", "proceso contralos statistical datos.", "proces contre statistical datos.", "procesos contables statistical datos."
"process control estadisticas methods." » "process control estadistica methods.", "process control estadistico methods.", "process control statistical methods.", "process control estadisticas metodos.", "process control estadisticas datos.", "procesos control estadisticas methods.", "proceso control estadisticas methods.", "procesal control estadisticas methods."

Try widening your search to All Fields.

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