Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
tu sach » thu sach, su sach, te sach
cuu tre » cua tre, cau tren, cau treo
qua ban » cua ban, qua quan
dua ban » dia ban, cua ban, mua ban
sach ty » sach y, sach tu, sach thu
ve cach » va cach, ve cac, ve canh
hieu ve » hieu va, hieu van
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty hang do hoi. hieu ve cach ((dua ban) OR (qua ban)) thanh tai ((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 cach ((dua ban) OR (qua ban)) thanh tai ((cuu tre) or (cua te))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty hang do hoi. hieu ve cach ((dua ban) OR (qua ban)) thanh tai ((cuu tre) or (cua te))*.