Perhaps you should try some spelling variations:
tieu tach » lieu thach, hieu cach, tieu danh
anh bang » anh hoang, anh quang, tinh bang
va tuong » va thuong, va thong, xa truong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
va tong » va thong, va trong, va cong

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu tach - anh bang ((va tong) or (va tuong)) cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu tach - anh bang ((va tong) OR (va tuong)) cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo tieu tach - anh bang ((va tong) or (va tuong)) cong tac toan cau*.