Perhaps you should try some spelling variations:
class mapping » glass mapping, claims mapping, case mapping
class tapping » glass mapping, class teaching, claims mapping
yang guang » yang yang, yan guan, yang liang
wing yang » wang yang, ying yang, wang yan
guang die » guang zhe, huang di, klang die
dong wei » wang wei, dong di, dong hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: wing yang guang die ((class mapping) OR (class tapping)) using ((dong sin) or (dong wei)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wing yang guang die ((class mapping) OR (class tapping)) using ((dong sin) OR (dong wei)) ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wing yang guang die ((class mapping) OR (class tapping)) using ((dong sin) or (dong wei)) ;*".