Perhaps you should try some spelling variations:
yang yang » wang yang, wang yan
hua gain » heat gain, run gain, hua ban
gain yan » gain a, nan yan
long shu » cong shu, tong shui, long du
wong sau » wong sam, wong siu, wong shiu
dong di » dong sin
yan jiu » yang jie, yang jin, pang jiu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((dong di) or (yang yang)) ya hua gain yan jiu ((long shu) OR (wong sau)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((dong di) OR (yang yang)) ya hua gain yan jiu ((long shu) OR (wong sau)) ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((dong di) or (yang yang)) ya hua gain yan jiu ((long shu) OR (wong sau)) ;*".