Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
tang quan » tang luan, nang quan, tong quan
dung cong » dung trong
thanh ban » thanh san, thanh van, thanh bac
hoc hieu » hoc thieu, hoc hien, doc hieu
tang qua » tang cua, tang quy, tang quang
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 qua) OR (tang quan)) 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 qua) OR (tang quan)) dung cong dan ((than ban) OR (thanh ban)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - anh ((tang qua) OR (tang quan)) dung cong dan ((than ban) or (thanh ban))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - anh ((tang qua) OR (tang quan)) dung cong dan ((than ban) or (thanh ban))*.