Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
thanh tung » thanh cong
nhung cong » dung cong, thong cong, nhung don
hieu lang » chieu sang, hieu quang, nhieu tang
hang cong » dang cong, hang nong, bang cong
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
tung va » trung va, tuong va, dung va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu tinh) or (hieu lang)) - thanh tung va ((nhung cong) or (hang cong)) tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu tinh) OR (hieu lang)) - thanh tung va ((nhung cong) OR (hang cong)) tac toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu tinh) or (hieu lang)) - thanh tung va ((nhung cong) or (hang cong)) tac toan cau*.