Perhaps you should try some spelling variations:
thien van » thi van
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
sach tu » sach thu, cach tu, sach ty
nang ma » tang ma, sang ma
nam duc » nam duoc, pham duc, nam thuc
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
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: so sach tu ((((nang ma) or (mang may))) or (nang cao)) hoi. thien van nam duc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tu ((((nang ma) OR (mang may))) OR (nang cao)) hoi. thien van nam duc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach tu ((((nang ma) or (mang may))) or (nang cao)) hoi. thien van nam duc van hanh vi cua tre*.