Perhaps you should try some spelling variations:
when changed » when change, been changed, we changed
changed file » change five, change fire, changed face
ying chang » jin chang, yi chang, yin hang
gong hui » tong hui, tong shui, wang hui
wong siu » wong shiu, kong siu, wong sau
so when » do when

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "yang ((ying chang) OR (ii gang)) so when changed file ((gong hui) OR (wong siu)) ;~".
• Adding a wildcard symbol may retrieve word variants: yang ((ying chang) OR (ii gang)) so when changed file ((gong hui) OR (wong siu)) ;*.