Perhaps you should try some spelling variations:
"procesos problems statistical methods." » "procesos process statistical methods.", "procesos penales statistical methods.", "procesos problems statistics methods.", "procesos problems estadisticas methods."
"procesos control statistical methods." » "process control statistical methods.", "proceso contra statistical methods.", "procesos contables statistical methods.", "procesos control statistics methods.", "procesos control estadisticas methods."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("procesos control statistical methods.") OR ("procesos problems statistical methods."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"procesos control statistical methods.\") OR (\"procesos problems statistical methods.\"))".
• Removing quotes may allow a broader search: (( procesos control statistical methods. ) OR ( procesos problems statistical methods. )).
• Adding a wildcard symbol may retrieve word variants: (("procesos control statistical methods.") OR ("procesos problems statistical methods."))*.