Perhaps you should try some spelling variations:
xuyen tac » xuyen tai, nguyen tac, thuyen tac
cong cong » cong dong, trong cong, dang cong
dung cong » dung trong
tac cac » thac cac, tai cac, tap cac
cac che » cac he, cac chien, cac chat
ve ky » va ky, ke ky
ve _ » va _
te y » ke y, te o, tu y

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 che đe co ban ((((ve _) or (te y))) or (ve ky)) thi ((cong cong) OR (dung cong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: xuyen tac cac che đe co ban ((((ve _) OR (te y))) OR (ve ky)) thi ((cong cong) OR (dung cong)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "xuyen tac cac che đe co ban ((((ve _) or (te y))) or (ve ky)) thi ((cong cong) OR (dung cong))".
• Adding a wildcard symbol may retrieve word variants: xuyen tac cac che đe co ban ((((ve _) or (te y))) or (ve ky)) thi ((cong cong) OR (dung cong))*.