Perhaps you should try some spelling variations:
sach kem » hanh kem
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, va danh
nam duc » nam duoc, pham duc, nam thuc
sang ma » tang ma, sang tao, mang may
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, nang cao, mang may
sach ty » sach y, sach tu, sach thu
vi cua » vai cua, di cua

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

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