Perhaps you should try some spelling variations:
chiet tach » chieu sach
doi chiet » doi chieu, doi chi, doi viet
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
cua van » cua vat, cua can, cua san
cua dan » cua dang, ca dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chiet tach - canh tranh ((((cua van) OR (cua ban))) or (cua dan)) cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - canh tranh ((((cua van) OR (cua ban))) OR (cua dan)) cong tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chiet tach - canh tranh ((((cua van) OR (cua ban))) or (cua dan)) cong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - canh tranh ((((cua van) OR (cua ban))) or (cua dan)) cong tac toan cau*.