Perhaps you should try some spelling variations:
"open detection series." » "open detection systems.", "open detection system.", "open defecation series.", "open defacation series.", "open directions series."
"event detection series." » "event detection systems.", "event detection system.", "defect detection series.", "object detection series."
"open education system." » "modern education system.", "open defecation system."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("open detection series.") OR ("event detection series."))) or ("open education system."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("open detection series.") OR ("event detection series."))) OR ("open education system.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"open detection series.\") OR (\"event detection series.\"))) or (\"open education system.\"))".
• Removing quotes may allow a broader search: (((( open detection series. ) OR ( event detection series. ))) or ( open education system. )).
• Adding a wildcard symbol may retrieve word variants: (((("open detection series.") OR ("event detection series."))) or ("open education system."))*.