Perhaps you should try some spelling variations:
thanh va » thanh van, hanh va, thanh ha
va thanh » gia thanh, ban thanh, va tinh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
va cao » va cac, va co, va dao
ha hoi » hoa hoi, xa hoi, va hoi
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca cua
va cam » va cham, va cac, va cai

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 ky dang ((ha hoi) OR (ha noi)). hieu ((va cam) or (va cao)) xuc va thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky dang ((ha hoi) OR (ha noi)). hieu ((va cam) OR (va cao)) xuc va thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky dang ((ha hoi) OR (ha noi)). hieu ((va cam) or (va cao)) xuc va thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky dang ((ha hoi) OR (ha noi)). hieu ((va cam) or (va cao)) xuc va thanh va cua tre*.