Perhaps you should try some spelling variations:
dung cong » dung trong
tang suc » trang suc, lang suc, tang su
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
theo co » cheo co, theo bo, theo cong
tang du » nang du, hang dau, dang duc

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

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