Perhaps you should try some spelling variations:
thien danh » thien anh, thien dang, thien thanh
thanh tung » thanh cong
duong manh » duong van
thiet anh » thien anh, thuyet anh, thich anh
tran dung » tran hung, tran quang, trung dung
tran dang » tran quang, tran hoang, tranh hang
manh toan » thanh toan, anh tuan, tinh toan
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 ((thiet anh) OR (thien danh)) - thanh tung ((tran dung) or (tran dang)) duong manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet anh) OR (thien danh)) - thanh tung ((tran dung) OR (tran dang)) duong manh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet anh) OR (thien danh)) - thanh tung ((tran dung) or (tran dang)) duong manh toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet anh) OR (thien danh)) - thanh tung ((tran dung) or (tran dang)) duong manh toan cau*.