Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu sang » chieu sang, hieu lang, hieu quang
trung cap » truong cao, trung tam
doc hieu » toc thieu, hoc thieu, hoc hien
cap tong » cap nong, cap hoang, gap trong
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
than ban » thanh ban, toan ban, than man

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 sang - thanh trung cap tong ((cong dan) or (cong tan)) than ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - thanh trung cap tong ((cong dan) OR (cong tan)) than ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - thanh trung cap tong ((cong dan) or (cong tan)) than ban*.