Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu xanh » chieu xanh, hieu manh, hieu nganh
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
trinh va » trinh van, trinh vat, trinh ve
van toan » van tuan, van tan, van thanh
va dung » van dung, va duong, vat dung

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 - hanh trinh va dung cong ((van toan) or (thanh pho)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh trinh va dung cong ((van toan) OR (thanh pho)) ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh trinh va dung cong ((van toan) or (thanh pho)) ban*.