Perhaps you should try some spelling variations:
thiet danh » thien anh, thien dang, tiep danh
thien danh » thien anh, thien dang, thien thanh
luan nhung » luan chung, luan hung, quan nhung
nhung cong » dung cong, thong cong, hang cong
tang luan » dung luan
manh toan » thanh toan, anh tuan, tinh toan
anh tang » anh bang, anh dang, anh nang
dan toan » van toan, dan than, xuan toan

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 danh) or (thien danh)) - anh tang luan nhung cong ((dan toan) OR (manh toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet danh) OR (thien danh)) - anh tang luan nhung cong ((dan toan) OR (manh toan)) cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet danh) or (thien danh)) - anh tang luan nhung cong ((dan toan) OR (manh toan)) cau*".