Perhaps you should try some spelling variations:
su sach » so sach, vu sach
so sanh » do sanh
va nang » van nang, da nang, cam nang
qua cac » cua cac
cac toc » cac toi, cac nuoc, cac thoi
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
toc va » hoc va, toc ta, tuc va
vi cua » vai cua, di cua
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: ((su sach) or (so sanh)) va nang x hoi. hieu qua cac toc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sanh)) va nang x hoi. hieu qua cac toc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) va nang x hoi. hieu qua cac toc va hanh vi cua tre*.