Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
canh tran » canh tranh, hanh trang, banh trang
dung dong » dung cong, vung dong, cong dong
ho chieu » theo chieu, hoc thieu, mot chieu
tran van » luan van
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (ho chieu)) xanh - canh tran van ((dung dong) OR (dung trong)) van tan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (ho chieu)) xanh - canh tran van ((dung dong) OR (dung trong)) van tan tap~".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (ho chieu)) xanh - canh tran van ((dung dong) OR (dung trong)) van tan tap*.