Perhaps you should try some spelling variations:
phung cong » nhung cong, phong cong, nhung chong
hien sach » dien sach, kien sach, thien hach
dan chinh » dang chinh, lan chinh, van chinh
chinh cau » chinh chau, chinh ca, chinh can
tran van » luan van
cong dan » cong san, cong tan, huong dan
tra van » ta van, trang van, tranh van

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 sach - thanh ((tra van) or (tran van)) phung cong dan chinh cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien sach - thanh ((tra van) OR (tran van)) phung cong dan chinh cau*.