Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh do » thanh de, thanh pho, thanh hoa
su sach » vu sach
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
long ha » dong ha, cong ha, dong hoa
nang ma » tang ma, sang ma, nang cao
so sach » so sanh, bo sach, co sach
va cam » va cham, va cac, va cao
do cua » doi cua, co cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) thu ((nang ma) or (long ha)) hoi. hieu va cam duc ban thanh do cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) thu ((nang ma) OR (long ha)) hoi. hieu va cam duc ban thanh do cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) thu ((nang ma) or (long ha)) hoi. hieu va cam duc ban thanh do cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) thu ((nang ma) or (long ha)) hoi. hieu va cam duc ban thanh do cua tre*.