Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
thanh vi » thanh va, thanh ve, nhanh vi
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang x hoi. ((hieu va) OR (lieu va)) cach thuc va ((thanh vi) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang x hoi. ((hieu va) OR (lieu va)) cach thuc va ((thanh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang x hoi. ((hieu va) OR (lieu va)) cach thuc va ((thanh vi) or (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang x hoi. ((hieu va) OR (lieu va)) cach thuc va ((thanh vi) or (hanh vi)) cua tre*.