Perhaps you should try some spelling variations:
cong thang » cong thanh, cang thang, cong thong
dang cong » dung cong
doc hieu » hoc thieu, hoc hien
nhan dan » phan dau, gian dan, nhan tai
dan dang » dang dang, dan dung, da dang
thang va » hang va, trang va, thong va
va dan » ca dan, va dao, va dau

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 - nhan dan dang cong thang va dan ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) tinh - nhan dan dang cong thang va dan ca.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (toc thieu)) tinh - nhan dan dang cong thang va dan ca*.