Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
dang xay » dang van, van xay
nam thuc » nam thuoc, am thuc, nam tu
thanh de » hanh de, thanh ve, thanh do
bach ky » bac ky
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu ve » hieu va, hieu van
cua tuc » cua tu, cua thuoc, luat tuc
cua duc » cua nuoc, cua quoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky dang xay hoi. hieu ve ((nam thuc) OR (nam thu)) dan thanh de ((cua tuc) or (cua duc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky dang xay hoi. hieu ve ((nam thuc) OR (nam thu)) dan thanh de ((cua tuc) OR (cua duc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky dang xay hoi. hieu ve ((nam thuc) OR (nam thu)) dan thanh de ((cua tuc) or (cua duc))".
• Adding a wildcard symbol may retrieve word variants: vu bach ky dang xay hoi. hieu ve ((nam thuc) OR (nam thu)) dan thanh de ((cua tuc) or (cua duc))*.