Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cam thuc » am thuc, nam thuc, cam thu
tai lang » tai cong, thi lan, tai san
thuc ban » thuoc ban, thuc dan, thu ban
hieu van » hieu va, thien van, lieu va
su sach » so sach
lang ha » long ha
vu sach » vu bach, vu khach
van cam » van nam, van lam, van cau
vi va » vai va, vu va, bi va

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: ((su sach) OR (vu sach)) tai lang ha noi. hieu van cam thuc ban thanh ((vi va) OR (vi van)) thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) tai lang ha noi. hieu van cam thuc ban thanh ((vi va) OR (vi van)) thiet~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) tai lang ha noi. hieu van cam thuc ban thanh ((vi va) OR (vi van)) thiet*.