Perhaps you should try some spelling variations:
chieu tinh » lieu tinh, chau tinh, kieu tinh
nhung cong » dung cong, thong cong, hang cong
nhan dang » nhan dan, phan dang, tran dang
cua nhung » va nhung
dang cua » dung cua, dong cua, mang cua
tap toan » tap quan, bai toan
tap doan » tap quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chieu tinh) or (trieu tinh)) - nhan dang cua nhung cong ((tap toan) OR (tap doan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu tinh) OR (trieu tinh)) - nhan dang cua nhung cong ((tap toan) OR (tap doan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu tinh) or (trieu tinh)) - nhan dang cua nhung cong ((tap toan) OR (tap doan)) ban".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu tinh) or (trieu tinh)) - nhan dang cua nhung cong ((tap toan) OR (tap doan)) ban*.