Perhaps you should try some spelling variations:
chiet tach » chieu sach
nhieu tang » chieu sang, hieu lang, nhiet nang
thanh tung » thanh cong
thong cong » trong cong, tong cong, thong thong
cap thong » cap tong, chap thuong, phap thong
tung cap » trung cap, cung cap, thong cap
tac toan » tap toan, hach toan, tich toan
tam toan » tap toan, tam than, pham toan

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 tung cap thong cong ((tac toan) OR (tam toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chiet tach) OR (nhieu tang)) - thanh tung cap thong cong ((tac toan) OR (tam toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chiet tach) or (nhieu tang)) - thanh tung cap thong cong ((tac toan) OR (tam toan)) cau".
• Adding a wildcard symbol may retrieve word variants: doi ((chiet tach) or (nhieu tang)) - thanh tung cap thong cong ((tac toan) OR (tam toan)) cau*.