Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh mang » nhanh mang, hanh trang, nhanh lang
hieu xanh » chieu xanh, hieu manh, hieu nganh
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 than » dan chan, ban than, van than
than tap » toan tap, han tap, phan tap

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 - ((anh tang) or (hanh mang)) va nhung cong dan than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - ((anh tang) OR (hanh mang)) va nhung cong dan than tap.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((anh tang) or (hanh mang)) va nhung cong dan than tap*.