Perhaps you should try some spelling variations:
ban thanh » ban hanh
van thiet » va thiet, dan thiet, can thiet
nang mai » nang ma, nang tai, lang mai
nam thuc » nam thuoc, am thuc, nam thu
ban hang » ngan hang
vu sach » su sach, vu khach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
v nang » va nang, vu nang, van nang
va nam » van nam, ha nam, va nay

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) OR (vu bach)) v nang mai hoi. hieu va nam thuc ((ban thanh) or (ban hang)) va van thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu bach)) v nang mai hoi. hieu va nam thuc ((ban thanh) OR (ban hang)) va van thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu bach)) v nang mai hoi. hieu va nam thuc ((ban thanh) or (ban hang)) va van thiet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (vu bach)) v nang mai hoi. hieu va nam thuc ((ban thanh) or (ban hang)) va van thiet*.