Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
cong tham » chong tham, cong thai, hong tham
tham dung » pham dung, tham cung, tham nhung
dung cong » dung trong
van thang » van thanh, van khang, van hang
hieu cac » hieu luc, hieu va, hieu van
cong van » cong vang, cong san, song van
thang ca » thang cua, hang ca, tang ca

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