Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
cuc ban » cua ban, cac ban, cuu ban
sach tu » sach thu, sach ty, sach uu
dang ma » dang mau, dang mam, dang mat
cach tu » cach thuc
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cao, 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: hoc ((sach tu) OR (cach tu)) dang ma hoi. hieu ((va cam) or (va cac)) cuc ban thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach tu) OR (cach tu)) dang ma hoi. hieu ((va cam) OR (va cac)) cuc ban thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach tu) OR (cach tu)) dang ma hoi. hieu ((va cam) or (va cac)) cuc ban thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach tu) OR (cach tu)) dang ma hoi. hieu ((va cam) or (va cac)) cuc ban thanh dai cua tre*.