Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
dang nhung » dang hung, dung nhung, sang nhung
tranh cua » doanh cua, manh cua
nhung tap » nhung bai, nhung cau, chung ta
cua dang » cua cong, cua ban
tap toan » tap doan, tap quan, bai toan
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: doc ((dieu hanh) or (chieu tinh)) - canh tranh cua dang nhung tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((dieu hanh) OR (chieu tinh)) - canh tranh cua dang nhung tap toan cao*.