Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
nhanh tinh » nhanh thanh, hanh trinh, nhan sinh
hanh tinh » hanh trinh, thanh tinh, canh tinh
dong cong » duong cong, dung cong, dang cong
cong lang » cong vang, cong luong, cong quang
lang than » lang thang, lang thanh, sang than
cua dong » chua dong, cua cong, cua dang
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((dieu hanh) or (hieu nganh)) - ((hanh tinh) OR (nhanh tinh)) cua dong cong lang than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((dieu hanh) OR (hieu nganh)) - ((hanh tinh) OR (nhanh tinh)) cua dong cong lang than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((dieu hanh) or (hieu nganh)) - ((hanh tinh) OR (nhanh tinh)) cua dong cong lang than cau".
• Adding a wildcard symbol may retrieve word variants: doc ((dieu hanh) or (hieu nganh)) - ((hanh tinh) OR (nhanh tinh)) cua dong cong lang than cau*.