Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
hieu van » thien van, lieu va, hieu ve
va doanh » van doanh, vay doanh, va danh
van cua » vang cua, ban cua, dan cua
lam duc » lam duoc, pham duc, nam duoc
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
ma hoi » xa hoi, ma hoa, me hoi
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: su sach ky nang ((ma hoi) OR (mai hoi)). ((hieu van) OR (hieu va)) lam duc va doanh van cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((ma hoi) or (mai hoi)). ((hieu van) OR (hieu va)) lam duc va doanh van cua te~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((ma hoi) or (mai hoi)). ((hieu van) OR (hieu va)) lam duc va doanh van cua te*.