Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh de » hanh ve
cam duc » cam xuc, cao duc, pham duc
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach vu ((nang xa) or (nang ma)) hoi. hieu va cam duc va ((hanh de) or (hanh kem)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach vu ((nang xa) OR (nang ma)) hoi. hieu va cam duc va ((hanh de) OR (hanh kem)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach vu ((nang xa) or (nang ma)) hoi. hieu va cam duc va ((hanh de) or (hanh kem)) cua tre*.