Perhaps you should try some spelling variations:
changed role » changed rome, changing role, changed world
changed file » change five, change fire, changed face
john ngosong » john song
long tail » long haul
chen john » chown john, chen jian, chen jean
long tip » long trip, long time, long did
sein » seine, ein, seen

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((long tip) or (long tail)) than ((changed role) OR (changed file)) chen john ngosong sein ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((long tip) OR (long tail)) than ((changed role) OR (changed file)) chen john ngosong sein ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((long tip) or (long tail)) than ((changed role) OR (changed file)) chen john ngosong sein ;".
• Adding a wildcard symbol may retrieve word variants: ((long tip) or (long tail)) than ((changed role) OR (changed file)) chen john ngosong sein ;*.