Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va cham » va chat, va tham
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
goc va » hoc va, doc va, uoc va
loc va » hoc va, luc va
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, 5 hoi

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 y nang ((x hoi) OR (x ho)). lieu va cham ((goc va) or (loc va)) hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((x hoi) OR (x ho)). lieu va cham ((goc va) OR (loc va)) hanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ((x hoi) OR (x ho)). lieu va cham ((goc va) or (loc va)) hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((x hoi) OR (x ho)). lieu va cham ((goc va) or (loc va)) hanh de cua tre*.