Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
hanh than » hanh han, hanh nhan, hanh phan
dung cong » dung trong
than cua » nhan cua, thai cua, ban cua
cua dung » cua dang, cua dong, qua dung
cong tan » cong tac, cong san, cong thanh
nhan tai » hang tai, van tai, toan tai
han tap » han tai, toan tap, nhan tao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu lang)) - hanh than cua dung cong tan ((han tap) or (nhan tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - hanh than cua dung cong tan ((han tap) OR (nhan tai)).
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu lang)) - hanh than cua dung cong tan ((han tap) or (nhan tai))*.