Perhaps you should try some spelling variations:
"proceso contralos statistical methods." » "proceso control statistical methods.", "proceso contra statistical methods.", "proces contreles statistical methods.", "procesos contables statistical methods."
"procesos tecnicas estadisticas methods." » "procesos tecnicas geoestadisticas methods.", "procesos mecanica estadistica methods.", "procesos tecnicas artisticas methods.", "procesos tecnicas estadisticas metodos.", "procesos tecnicas estadisticas datos.", "procesos tecnicas estadisticas medicas.", "progresos tecnicos estadisticas methods.", "procesos teorias estadisticas methods.", "propuestas tecnicas estadisticas 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: (("proceso contralos statistical methods.") OR ("procesos tecnicas estadisticas methods."))~.
• Removing quotes may allow a broader search: (( proceso contralos statistical methods. ) or ( procesos tecnicas estadisticas methods. ))~.
• Adding a wildcard symbol may retrieve word variants: (("proceso contralos statistical methods.") or ("procesos tecnicas estadisticas methods."))*.