Perhaps you should try some spelling variations:
cong thang » cong thanh, cang thang, cong thong
dung cong » dung trong
doc hieu » hoc thieu, hoc hien
nhan dan » phan dau, gian dan, nhan tai
dan dung » van dung, tin dung, ap dung
thang ca » thang cua, hang ca, tang ca
ca dan » cac dan, ca dao

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