Perhaps you should try some spelling variations:
truong trung » tieng trung
manh truong » manh trung, manh tuong, anh truong
trung nhung » trong nhung, trung hung, trung ngung
nhung cong » dung cong, thong cong, hang cong
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
tran doan » trang doan, tran hoan, toan doanh
tan doan » tap doan, van doan, toan doanh

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 sang) OR (hieu lang)) - manh truong trung nhung cong ((tan doan) or (tran doan)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - manh truong trung nhung cong ((tan doan) OR (tran doan)) van.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu lang)) - manh truong trung nhung cong ((tan doan) or (tran doan)) van".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu lang)) - manh truong trung nhung cong ((tan doan) or (tran doan)) van*.