Perhaps you should try some spelling variations:
thien chanh » thien thanh, thien chinh, hien hanh
thanh tuong » thanh thuong, thanh tung, thanh huong
thien danh » thien anh, thien dang, thien thanh
trong mach » trong cac, trong minh, trong anh
mach toan » manh toan, hach toan, mach tuan
cua dung » cua dong, qua dung, cua rung
cua dang » cua cong, cua ban
toan cau » 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 danh) or (thien chanh)) - thanh tuong ((cua dung) OR (cua dang)) trong mach toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien danh) OR (thien chanh)) - thanh tuong ((cua dung) OR (cua dang)) trong mach toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien danh) or (thien chanh)) - thanh tuong ((cua dung) OR (cua dang)) trong mach toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien danh) or (thien chanh)) - thanh tuong ((cua dung) OR (cua dang)) trong mach toan cau*.