Perhaps you should try some spelling variations:
dang cong » dung cong
doc hieu » hoc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
tu dang » thu dang, tu dong, su dang
dan van » dang van, doan van, dao van
van tan » van tuan, van ban, van tai
tan ca » tan cua, tang ca, dan ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) OR (toc thieu)) tinh - phan tu dang cong dan van tan ca~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) OR (toc thieu)) tinh - phan tu dang cong dan van tan ca".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) OR (toc thieu)) tinh - phan tu dang cong dan van tan ca*.