Perhaps you should try some spelling variations:
ngung cong » nhung cong, dung cong, nganh cong
doi chieu » doc hieu, doi chi, ho chieu
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
chat » nhat, phat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (toc thieu)) tach - hanh tinh chat ngung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (toc thieu)) tach - hanh tinh chat ngung cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (toc thieu)) tach - hanh tinh chat ngung cong tac toan cau*.