Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
trang cua » tranh cua, trung cua, thang cua
hoc hieu » hoc thieu, hoc hien, doc hieu
tang cua » mang cua, hang cua, tang luan
dan toan » van toan, dan than, manh toan
ban than » ban thanh, van thanh, ban hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - hanh ((trang cua) or (tang cua)) nhung cong ((dan toan) or (ban than)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - hanh ((trang cua) OR (tang cua)) nhung cong ((dan toan) OR (ban than)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh ((trang cua) or (tang cua)) nhung cong ((dan toan) or (ban than)) ban*.