Perhaps you should try some spelling variations:
thanh trung » thanh tung
hien hanh » dieu hanh
cua nong » cua cong, cuu nong, cua song
cua dong » chua dong, cua cong, cua dang
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien hanh - thanh trung ((cua nong) or (cua dong)) ((cong dan) OR (cong san)) chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien hanh - thanh trung ((cua nong) OR (cua dong)) ((cong dan) OR (cong san)) chan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien hanh - thanh trung ((cua nong) or (cua dong)) ((cong dan) OR (cong san)) chan cau".
• Adding a wildcard symbol may retrieve word variants: hoc hien hanh - thanh trung ((cua nong) or (cua dong)) ((cong dan) OR (cong san)) chan cau*.