Perhaps you should try some spelling variations:
"process control estadisticas methods." » "process control estadistica methods.", "process control estadistico methods.", "process control statistical methods.", "process control estadisticas metodos.", "process control estadisticas medicas."
"process control estadisticas datos." » "process control estadistica datos.", "process control estadistico datos.", "process control statistical datos.", "process control estadistica casos.", "process control estadisticas metodos.", "process control estadisticas de."

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 ("process control estadisticas datos."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"process control estadisticas methods.\") OR (\"process control estadisticas datos.\"))".
• Removing quotes may allow a broader search: (( process control estadisticas methods. ) OR ( process control estadisticas datos. )).
• Adding a wildcard symbol may retrieve word variants: (("process control estadisticas methods.") OR ("process control estadisticas datos."))*.