Perhaps you should try some spelling variations:
long thanh » luong thanh, long han, long trinh
hong than » hong tan, hong hai
week ying » wee ling, week nine
six week » six weeks, six we, six west
ying thi » ying zhu, dang thi, ying ph
ya six » a six
dong » doing, done, pong

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((dong sin) OR (wang yan)) ya six week ying thi ((hong than) OR (long thanh)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((dong sin) or (wang yan)) ya six week ying thi ((hong than) OR (long thanh)) ;~".
• Adding a wildcard symbol may retrieve word variants: ((dong sin) or (wang yan)) ya six week ying thi ((hong than) OR (long thanh)) ;*.