Perhaps you should try some spelling variations:
dung thuong » dung trong, hang thuong, cong thuong
hieu quang » thieu quang, hieu quan, hieu qua
thanh tran » thanh trang, thanh toan, thanh tra
dung tuong » dung truong, dung trong, dung luong
doc hieu » toc thieu, hoc thieu, hoc hien
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu quang - ((thanh tran) or (thanh san)) tuan ((dung tuong) OR (dung thuong)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu quang - ((thanh tran) OR (thanh san)) tuan ((dung tuong) OR (dung thuong)) dan than cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu quang - ((thanh tran) or (thanh san)) tuan ((dung tuong) OR (dung thuong)) dan than cau*".