Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
van nang » van quang, van ban, van dong
nang dua » nang du, nang suat, nang quan
dua cong » cua cong, qua cong, duc cong
dong dan » dong danh, duong dan, dong san
dan phan » doan phan, dan chan, van phan
phan cac » nhan cach, phan dau, phan lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hop ((hieu lang) or (chieu sach)) - van nang dua cong dong dan phan cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hop ((hieu lang) OR (chieu sach)) - van nang dua cong dong dan phan cac*.