Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
cao thuc » cao thuoc, bao thuc, can thuc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
danh di » danh du, xanh di, danh dien
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky nang xa hoi. hieu va cao thuc vat ((danh di) or (hanh de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky nang xa hoi. hieu va cao thuc vat ((danh di) OR (hanh de)) cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang xa hoi. hieu va cao thuc vat ((danh di) or (hanh de)) cua tre*.