Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
truong va » truong dai, truong cao, truong dao
dung cong » dung trong
hoi hieu » hoi phieu, hoi tieu, moi hieu
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - thanh ((trung cua) or (truong va)) dung cong tap toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - thanh ((trung cua) OR (truong va)) dung cong tap toan tap.
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - thanh ((trung cua) or (truong va)) dung cong tap toan tap*.