Perhaps you should try some spelling variations:
thuyet tinh » thuyet trinh, thuyet dinh, thuyet minh
dung quang » dang quang, luong quang, dung luan
dung quan » dung luan, luong quan, dang quang
trong tan » trong quan, trong cac, trong ca
tan toan » tan tran, tap toan, van toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thuyet tinh) or (thuyet kinh)) - thanh ((dung quang) OR (dung quan)) dung trong tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thuyet tinh) OR (thuyet kinh)) - thanh ((dung quang) OR (dung quan)) dung trong tan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thuyet tinh) or (thuyet kinh)) - thanh ((dung quang) OR (dung quan)) dung trong tan toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thuyet tinh) or (thuyet kinh)) - thanh ((dung quang) OR (dung quan)) dung trong tan toan cao*.