Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
cua viet » ca viet, hoa viet, cua vat
dang xay » dang van, van xay
doi cua » dai cua, hoi cua
thuc va » thuc dan, thuc day
hieu va » lieu va, hieu qua
hieu ve » hieu van
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
sai ky » sac ky
te sai » te tai, te bai, te lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sai ky dang xay hoi. ((hieu ve) or (hieu va)) cam ((thuc va) OR (thuc vat)) thanh doi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sai ky dang xay hoi. ((hieu ve) OR (hieu va)) cam ((thuc va) OR (thuc vat)) thanh doi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sai ky dang xay hoi. ((hieu ve) or (hieu va)) cam ((thuc va) OR (thuc vat)) thanh doi cua viet".
• Adding a wildcard symbol may retrieve word variants: te sai ky dang xay hoi. ((hieu ve) or (hieu va)) cam ((thuc va) OR (thuc vat)) thanh doi cua viet*.