Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
tong cong » trong cong, cong cong, dung cong
canh dan » canh van, sanh dan, thanh dan
cong san » cong tac
toan ban » van ban
ho hieu » ho chieu, hoi hieu, nho hieu
ca tong » ca trong, cap tong, cua tong

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - canh dan ca tong cong san ((toan tap) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - canh dan ca tong cong san ((toan tap) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - canh dan ca tong cong san ((toan tap) or (toan ban))*.