Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
tang luan » dung luan
theo hau » theo dau, theo mau, theo phap
hau sach » khau sach, cau sach, ham sach
tang cua » mang cua, hang cua, thong cua
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hau sach - hanh ((tang cua) or (tang luan)) nhung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hau sach - hanh ((tang cua) OR (tang luan)) nhung cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo hau sach - hanh ((tang cua) or (tang luan)) nhung cong tac toan cau*.