Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
thuc ban » thuoc ban, thuc dan, thu ban
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
va chat » van chat, va phat, cao chat
va cham » va tham
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di 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 ty ((hang va) or (tang ma)) hoi. hieu ((va cham) OR (va chat)) thuc ban thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((hang va) OR (tang ma)) hoi. hieu ((va cham) OR (va chat)) thuc ban thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((hang va) or (tang ma)) hoi. hieu ((va cham) OR (va chat)) thuc ban thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((hang va) or (tang ma)) hoi. hieu ((va cham) OR (va chat)) thuc ban thanh vi cua tre*.