Perhaps you should try some spelling variations:
chiet tach » chieu sach
nhieu tang » chieu sang, hieu lang, nhiet nang
thong cong » trong cong, tong cong, thong thong
trung cap » truong cao
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: doi ((chiet tach) or (nhieu tang)) - thanh ((trung cap) OR (trung tam)) thong cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chiet tach) OR (nhieu tang)) - thanh ((trung cap) OR (trung tam)) thong cong tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chiet tach) or (nhieu tang)) - thanh ((trung cap) OR (trung tam)) thong cong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: doi ((chiet tach) or (nhieu tang)) - thanh ((trung cap) OR (trung tam)) thong cong tac toan cau*.