Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hoi » thanh hoai, thanh hoa, thanh hai
nang dai » nang dau, lang dai, nang cai
nang tai » hang tai, tang tai, sang tai
tu sach » thu sach, su sach, te sach
cay dua » chay dua, cay lua, ca dua
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
cam dua » ca dua, chay dua, cach dua
hieu ve » hieu va, hieu van

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