Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
phuong dan » phuong danh, phuong doan, huong dan
theo hieu » theo tieu, thien hieu, thuc hieu
tang tuan » trang tuan, tang quan, tang tan
tang luan » dung luan
dan toan » van toan, dan than, manh 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: ((theo hieu) OR (theo chieu)) lang - hanh ((tang tuan) or (tang luan)) doan phuong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo hieu) OR (theo chieu)) lang - hanh ((tang tuan) OR (tang luan)) doan phuong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo hieu) OR (theo chieu)) lang - hanh ((tang tuan) or (tang luan)) doan phuong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((theo hieu) OR (theo chieu)) lang - hanh ((tang tuan) or (tang luan)) doan phuong dan toan cau*.