Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
ban thanh » ban hanh, ban hang
tu sach » thu sach, su sach, te sach
cac duc » cac du, cao duc, cac dac
cuu tre » cau tren, cau treo
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cua triet, dua tren
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
ve cac » va cac, vien cac

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