Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
thuc hung » thuc chung, thuc nhung, thuc dung
hung cong » nhung cong, hung cuong, phung cong
cong toan » cong tan, cong hoan, cong tuan
toan phan » thanh phan, toan ban, hoa phan
phan dau » phan tu, hang dau
tinh da » tinh va, tinh gia, tinh lao
da thuc » dan thuc, dai thuc, dam thuc

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sach) or (hieu lang)) - tinh da thuc hung cong toan phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (hieu lang)) - tinh da thuc hung cong toan phan dau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (hieu lang)) - tinh da thuc hung cong toan phan dau*.