Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
danh dai » danh dau, danh sai, vanh dai
danh di » danh du, xanh di, danh dien
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet

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

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((lang xa) OR (nang ma)) hoi. lieu va cac thuc va ((danh dai) OR (danh di)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((lang xa) or (nang ma)) hoi. lieu va cac thuc va ((danh dai) OR (danh di)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sach y ((lang xa) or (nang ma)) hoi. lieu va cac thuc va ((danh dai) OR (danh di)) cua tre*.