Perhaps you should try some spelling variations:
khong cong » thong cong, khong cang, chong cong
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh tang » hanh trang, hanh mang, hanh tung
hua khong » hoa khong, cua khong, hoac khong
doc hieu » toc thieu, 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 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 xanh - ((hanh tang) OR (anh tang)) hua khong cong dan van ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((hanh tang) or (anh tang)) hua khong cong dan van ban*.