Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu luc » hieu luat, hieu qua
thanh va » thanh van, hanh va, thanh ha
cham xuc » cam xuc, chat xuc, cham soc
so sach » so sanh, bo sach, co sach
xuc ban » duc ban, cuc ban, quoc ban
cua tre » cua te, cuu tre, cua triet
hieu tu » chieu tu, hieu tuc, hien tu
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky dang » ky nang, ky danh
ky dong » ly dong, ky cong, ty dong
va cua » va chua, via cua, ca cua

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 dong) or (ky dang)) hoa hoi. ((hieu tu) or (hieu luc)) cham xuc ban thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ky dong) OR (ky dang)) hoa hoi. ((hieu tu) OR (hieu luc)) cham xuc ban thanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ((ky dong) or (ky dang)) hoa hoi. ((hieu tu) or (hieu luc)) cham xuc ban thanh va cua tre*.