Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
hanh hang » thanh hang, hang hang, hanh han
dung cong » dung trong
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hieu lang - hanh hang va ((nhung cong) or (dung cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - hanh hang va ((nhung cong) OR (dung cong)) dan toan cao*.