Perhaps you should try some spelling variations:
dung cong » dung trong
hieu lang » chieu sang, hieu quang, nhieu tang
thanh ban » thanh san, thanh van, thanh bac
hoc hieu » hoc thieu, hoc hien, doc hieu
anh tang » anh bang, anh dang, anh nang
tang quy » tan quy, nang quy, tang quan
quy dung » duy dung, qua dung, quyet dung
cong dan » cong san, cong tan, huong dan
than ban » toan ban, than man, nhuan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - anh tang quy dung cong dan ((than ban) or (thanh ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - anh tang quy dung cong dan ((than ban) OR (thanh ban)).
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - anh tang quy dung cong dan ((than ban) or (thanh ban))*.