Perhaps you should try some spelling variations:
tieng trung » truong trung
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
tang luan » dung luan
hoi hieu » hoi phieu, hoi tieu, moi hieu
tang cua » mang cua, hang cua, thong cua
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: hoi hieu lang - hanh ((tang cua) OR (tang luan)) ((nhung cong) or (tieng trung)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - hanh ((tang cua) OR (tang luan)) ((nhung cong) OR (tieng trung)) dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - hanh ((tang cua) OR (tang luan)) ((nhung cong) or (tieng trung)) dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - hanh ((tang cua) OR (tang luan)) ((nhung cong) or (tieng trung)) dan than cau*.