Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
cong tham » chong tham, cong thai, hong tham
tham hang » pham hang, thai hang, tham lang
hang cong » dang cong, hang nong, bang cong
hieu van » hieu va, thien van, lieu va
cong dan » cong san, cong tan, huong dan
ca ca » ca cac, ca cua, ca cao

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 van) or (chieu sach)) - thanh cong tham hang cong dan ca ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu van) OR (chieu sach)) - thanh cong tham hang cong dan ca ca.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu van) or (chieu sach)) - thanh cong tham hang cong dan ca ca*.