Perhaps you should try some spelling variations:
quyen tai » nguyen tai, truyen tai, luyen thi
cong cong » cong dong, trong cong, dung cong
xuyen tai » xuyen tac, nguyen tai, truyen tai
cac khoi » cac thoi, cac khoan, cach thoi
cac khu » cac thu, cac kieu
ban le » ban ve
y thuc » ty thuc, y thuoc, _ thuc
y thu » ly thu, ky thu, _ thu

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

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