Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dua tren » dung tren
hang tai » hang va, dung tai
tham tuc » tham thuc, thai tuc, nham thuc
va thanh » gia thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
ky hang » ky nang, ly hang, ky dang
tai hoi » tai khoi, dai hoi, tai hai
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thuat
sach ky » sac ky, sach y, sach ty
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 ky hang tai hoi. hieu va tham tuc ((va thanh) OR (ban thanh)) lap ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky hang tai hoi. hieu va tham tuc ((va thanh) OR (ban thanh)) lap ((dua tren) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky hang tai hoi. hieu va tham tuc ((va thanh) OR (ban thanh)) lap ((dua tren) or (cua te))*".