Perhaps you should try some spelling variations:
khong cong » thong cong, khong cang, chong cong
hanh tang » hanh trang, hanh mang, hanh tung
hua khong » hoa khong, cua khong, hoac khong
doc hieu » hoc thieu, hoc hien
anh tang » anh bang, anh dang, anh nang
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao van

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)) xanh - ((hanh tang) or (anh tang)) hua khong cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) xanh - ((hanh tang) OR (anh tang)) hua khong cong dan van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) OR (toc thieu)) xanh - ((hanh tang) or (anh tang)) hua khong cong dan van ban".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) OR (toc thieu)) xanh - ((hanh tang) or (anh tang)) hua khong cong dan van ban*.