Perhaps you should try some spelling variations:
nang dau » hang dau, xang dau, nang du
su sach » so sach, vu sach
dau hoi » cau hoi, dai hoi, dan hoi
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va bao » va bai
bao va » bao ve, tao va, ban va
va cua » va chua, via cua, ca cua
bo va » do va, so va, co va

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