Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, tran tuan
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung cap, dung cua
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong tac » cong ty
tac toan » tap toan, tam toan, hach 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 hieu lang - thanh ((trung cua) or (trung tuan)) dung cong tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - thanh ((trung cua) OR (trung tuan)) dung cong tac toan cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - thanh ((trung cua) or (trung tuan)) dung cong tac toan cao*.