Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hoi » thanh hoai, thanh hoa, thanh hai
nang mai » nang ma, nang tai, lang mai
tu sach » thu sach, su sach, te sach
cay dua » cay lua, ca dua, cay nua
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
cam dua » ca dua, cach dua
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang mai hoi. hieu ve ((((cam dua) OR (chay dua))) or (cay dua)) ban thanh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang mai hoi. hieu ve ((((cam dua) OR (chay dua))) OR (cay dua)) ban thanh hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang mai hoi. hieu ve ((((cam dua) OR (chay dua))) or (cay dua)) ban thanh hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang mai hoi. hieu ve ((((cam dua) OR (chay dua))) or (cay dua)) ban thanh hoi cua tre*.