Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu tinh » trieu tinh, lieu tinh, chau tinh
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
trung va » truong va, trang va, trung ha
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: hoc ((chieu tinh) or (hieu lang)) - thanh trung va nhung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu tinh) OR (hieu lang)) - thanh trung va nhung cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu tinh) or (hieu lang)) - thanh trung va nhung cong tac toan cau*.