Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, nhung don
tieu xanh » tieu danh, chieu xanh, dieu hanh
hang cong » dang cong, hang nong, bang cong
ban quan » van quan
bai toan » bai tap
toan cao » toan ban, toan tap
anh ban » anh bang, anh bai, anh van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu xanh - anh ban quan ((nhung cong) or (hang cong)) bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu xanh - anh ban quan ((nhung cong) OR (hang cong)) bai toan cao.
• Adding a wildcard symbol may retrieve word variants: theo tieu xanh - anh ban quan ((nhung cong) or (hang cong)) bai toan cao*.