Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
dai cuu » dai cua, dai huu
cay dua » chay dua, cay lua, cay nua
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
sang ma » nang ma, sang tao, mang may
cuu tre » cua tre, cau tren, cau treo
ca dua » ca cua, ca da, ca lua

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 ((sang ma) or (tang ma)) hoa. hieu van ((cay dua) OR (ca dua)) ban thanh dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((sang ma) OR (tang ma)) hoa. hieu van ((cay dua) OR (ca dua)) ban thanh dai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((sang ma) or (tang ma)) hoa. hieu van ((cay dua) OR (ca dua)) ban thanh dai cuu tre*".