Perhaps you should try some spelling variations:
thien chanh » thien thanh, thien chinh, hien hanh
thien danh » thien anh, thien dang, thien thanh
manh trung » manh tung, thanh trung, manh hung
trung cua » truong cua, trung tuan, trung cap
cong nong » cong dong, cong cong, cong trong
nong dan » cong dan, nong san, nguong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien chanh) or (thien danh)) - manh trung cua cong nong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien chanh) OR (thien danh)) - manh trung cua cong nong dan toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((thien chanh) or (thien danh)) - manh trung cua cong nong dan toan cao*.