Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh hang » thanh hang, hang hang, hanh han
va phuong » va thuong, cac phuong
hoc hieu » hoc thieu, hoc hien, doc hieu
van toan » van tuan, van tan, van thanh
ban hanh » 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 hang va phuong cong ((van toan) or (ban hanh)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - hanh hang va phuong cong ((van toan) OR (ban hanh)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh hang va phuong cong ((van toan) or (ban hanh)) ban*.