Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hoi hieu » hoi phieu, hoi tieu, moi hieu
tang cua » mang cua, tang luan, thong cua
hang cua » mang cua, hang ca, huong cua
cong tac » cong ty
tac phan » tac pham, tai phan, tac phat
phan dau » phan tu, hang dau
ho hieu » ho chieu, nho hieu, co hieu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho hieu) OR (hoi hieu)) lang - hanh ((tang cua) OR (hang cua)) nhung cong tac phan dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho hieu) OR (hoi hieu)) lang - hanh ((tang cua) or (hang cua)) nhung cong tac phan dau~".
• Adding a wildcard symbol may retrieve word variants: ((ho hieu) OR (hoi hieu)) lang - hanh ((tang cua) or (hang cua)) nhung cong tac phan dau*.