Perhaps you should try some spelling variations:
trang thiet » trong thiet, trinh thiet, toan thiet
theo chieu » ho chieu, theo chu, thi chieu
hanh trang » thanh trung, canh tranh, hanh trinh
luong cong » dung cong, trong cong, cong cong
xung cong » xuong cong, dung cong, duong cong
doan van » doan va, hoang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((theo chieu) or (theo tieu)) xanh - hanh trang thiet ((xung cong) OR (luong cong)) doan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (theo tieu)) xanh - hanh trang thiet ((xung cong) OR (luong cong)) doan van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (theo tieu)) xanh - hanh trang thiet ((xung cong) OR (luong cong)) doan van ban".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (theo tieu)) xanh - hanh trang thiet ((xung cong) OR (luong cong)) doan van ban*.