Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
cuu tre » cua tre, cau tren, cau treo
cac cua » cach cua, cac qua, ca cua
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va
hang do » hang doi, dang do, hang di
ty hang » ly hang, ty xang, thi hang
do hoi » do choi, do hoai, do thoi
cua te » cua tu

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