Perhaps you should try some spelling variations:
xuyen tac » xuyen tai, nguyen tac, thuyen tac
cac chat » cao chat, cac thuat, cac nha
thi cong » tai cong, thien cong
cac thu » cach thuc, cac thoi
cac che » cac he, cac chien, sach che
ban ve » ban va
y thi » ky thi, y thai, ly thi
dong » dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: xuyen tac ((cac thu) or (((cac che) or (cac chat)))) đe co ((ban le) OR (ban ve)) y thi cong dong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: xuyen tac ((cac thu) OR (((cac che) OR (cac chat)))) đe co ((ban le) OR (ban ve)) y thi cong dong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "xuyen tac ((cac thu) or (((cac che) or (cac chat)))) đe co ((ban le) OR (ban ve)) y thi cong dong".
• Adding a wildcard symbol may retrieve word variants: xuyen tac ((cac thu) or (((cac che) or (cac chat)))) đe co ((ban le) OR (ban ve)) y thi cong dong*.