Perhaps you should try some spelling variations:
xuyen tac » xuyen tai, nguyen tac, thuyen tac
cong cong » trong cong, dung cong, dang cong
cac che » cac chien, cac chat, sach che
ca chu » cua chu, ca chua, cac chu
ban ve » ban va
y thi » ky thi, y thai, ly thi
ve y » ve ky, ve _, ke y
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 ((ca chu) or (((cac che) or (cac he)))) đe co ban ve y thi ((cong cong) OR (cong dong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: xuyen tac ((ca chu) OR (((cac che) OR (cac he)))) đe co ban ve y thi ((cong cong) OR (cong dong)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "xuyen tac ((ca chu) or (((cac che) or (cac he)))) đe co ban ve y thi ((cong cong) OR (cong dong))".
• Adding a wildcard symbol may retrieve word variants: xuyen tac ((ca chu) or (((cac che) or (cac he)))) đe co ban ve y thi ((cong cong) OR (cong dong))*.