Perhaps you should try some spelling variations:
huyen cao » khuyen cao, huyen bao, huyen cho
luyen tap » tuyen tap, luyen thi
cong cong » cong dong, trong cong, dang cong
dung cong » dung trong
cac che » cac he, cac chien, cac chat
ban vat » bang vat, ben vat, ban va
ly te » y te, ly ke, ly ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((huyen cao) or (luyen tap)) cac che đe co ban vat ly te ((cong cong) OR (dung cong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((huyen cao) OR (luyen tap)) cac che đe co ban vat ly te ((cong cong) OR (dung cong)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((huyen cao) or (luyen tap)) cac che đe co ban vat ly te ((cong cong) OR (dung cong))".
• Adding a wildcard symbol may retrieve word variants: ((huyen cao) or (luyen tap)) cac che đe co ban vat ly te ((cong cong) OR (dung cong))*.