Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu van
van cua » vang cua, ban cua, dan cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
tuc va » thuc va, truc va, tuc xa
xuc va » duc va, luc va, xac va
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 tang ma hoa. ((hieu ve) or (hieu va)) cam ((xuc va) OR (tuc va)) doanh van cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ma hoa. ((hieu ve) OR (hieu va)) cam ((xuc va) OR (tuc va)) doanh van cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ma hoa. ((hieu ve) or (hieu va)) cam ((xuc va) OR (tuc va)) doanh van cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ma hoa. ((hieu ve) or (hieu va)) cam ((xuc va) OR (tuc va)) doanh van cua te*.