Perhaps you should try some spelling variations:
cach thuc » anh thuc
quyen vo » quyen so, huyen vo, quyen con
thi cong » tai cong, thien cong
cac thu » cac thoi
co benh » con benh, so benh, o benh
vat y » vat ly, vat _
y thi » ky thi, y thai, ly thi
benh » bienh, beenh
ben » bien, been
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: quyen vo ((cach thuc) OR (cac thu)) đe ((co benh) or (do ben)) vat y thi cong dong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: quyen vo ((cach thuc) OR (cac thu)) đe ((co benh) OR (do ben)) vat y thi cong dong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "quyen vo ((cach thuc) OR (cac thu)) đe ((co benh) or (do ben)) vat y thi cong dong".
• Adding a wildcard symbol may retrieve word variants: quyen vo ((cach thuc) OR (cac thu)) đe ((co benh) or (do ben)) vat y thi cong dong*.