Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
ho chieu » theo chieu, doi chieu, mot chieu
tranh va » tranh van, trang va, trinh va
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
than tap » toan tap, han tap, phan tap
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (hoc thieu)) xanh - canh tranh va hang ((cong dan) OR (cong tan)) than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) xanh - canh tranh va hang ((cong dan) OR (cong tan)) than tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) xanh - canh tranh va hang ((cong dan) OR (cong tan)) than tap".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) xanh - canh tranh va hang ((cong dan) OR (cong tan)) than tap*.