Perhaps you should try some spelling variations:
tranh luan » trinh luan, trinh luat, doanh luan
hien sang » hien trang, khien bang, chieu sang
dung cong » dung trong
dan thanh » dang thanh, danh thanh, ban thanh
thanh cac » hanh cac, thanh bac, thanh ca
tranh ap » tranh chap, tranh ban, tranh cac
cong dan » cong san, cong tan, huong dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien sang - hanh ((tranh ap) or (tranh luan)) dung cong dan thanh cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien sang - hanh ((tranh ap) OR (tranh luan)) dung cong dan thanh cac*.