Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, quyen cap
luyen thi » nguyen thi
cong cong » cong dong, trong cong, dung cong
bang vat » bang va, dang vat, cang vat
cac che » cac he, cac chien, cac chat
ban vat » ben vat, ban va, van vat
te cong » tai cong, thi cong, thu cong

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

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