Perhaps you should try some spelling variations:
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va bao » va bai
bao bo » bac bo, ban bo, nao bo
va anh » van anh, va danh, va banh
va cua » va chua, via cua, ca cua

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 y nang cao hoi. hieu va bao bo ((va anh) or (va hanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang cao hoi. hieu va bao bo ((va anh) OR (va hanh)) va cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y nang cao hoi. hieu va bao bo ((va anh) or (va hanh)) va cua tre*.