Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hoc sach » hoc sinh, hoc cac
thanh va » thanh van, hanh va, thanh ha
so sach » so sanh, bo sach, co sach
hoc anh » hoc nganh, hoc nhanh, ngoc anh
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
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 (((hoc sach) OR (hoc anh)))) ky nang x hoi. lieu va cam duc ban thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (((hoc sach) OR (hoc anh)))) ky nang x hoi. lieu va cam duc ban thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (((hoc sach) OR (hoc anh)))) ky nang x hoi. lieu va cam duc ban thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (((hoc sach) OR (hoc anh)))) ky nang x hoi. lieu va cam duc ban thanh va cua tre*.