Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu nganh » vien nganh, hiem ngan, hieu manh
nang thanh » dang thanh, tang thanh, nhanh thanh
hieu xanh » chieu xanh, hieu manh, dieu hanh
cong nang » cong ngang, cong lang, cong nong
thanh tu » hanh tu, nhanh tu, thanh tung
va hang » van hang, va nang, va hanh
va lang » va nang, hoa lang

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) or (hieu nganh)) - thanh trung ((va hang) OR (va lang)) cong nang thanh tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (hieu nganh)) - thanh trung ((va hang) OR (va lang)) cong nang thanh tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) or (hieu nganh)) - thanh trung ((va hang) OR (va lang)) cong nang thanh tu".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (hieu nganh)) - thanh trung ((va hang) OR (va lang)) cong nang thanh tu*.