Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, va tinh, le thanh
so sach » so sanh, bo sach, co sach
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca 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: ((so sach) or (thuoc sach)) ky nang x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (thuoc sach)) ky nang x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (thuoc sach)) ky nang x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (thuoc sach)) ky nang x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua tre*.