Perhaps you should try some spelling variations:
nhanh lang » nhanh quang, nhanh thang, nhan dang
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hoi hieu » hoi phieu, hoi tieu, moi hieu
tan toan » tap toan, van toan, dan toan
lang va » lang van, hang va, lang ha

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 - nhanh lang va ((nhung cong) or (thong cong)) ((tan toan) OR (tan tran)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - nhanh lang va ((nhung cong) OR (thong cong)) ((tan toan) OR (tan tran)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - nhanh lang va ((nhung cong) or (thong cong)) ((tan toan) OR (tan tran)) cau".
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - nhanh lang va ((nhung cong) or (thong cong)) ((tan toan) OR (tan tran)) cau*.