Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
sach thu » sach thue, sach thieu, sach tham
thu bang » thu ban, thu hang, chu bang
tu sach » thu sach, su sach, te sach
van cua » vang cua, ban cua, dan cua
hieu ve » hieu va, hieu van
hieu vu » hieu va, hieu su, dieu vu
bang xa » lang xa, bang va, mang xa
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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 thu bang xa hoi. ((hieu vu) or (hieu ve)) cham ((xuc va) OR (tuc va)) doanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu bang xa hoi. ((hieu vu) OR (hieu ve)) cham ((xuc va) OR (tuc va)) doanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu bang xa hoi. ((hieu vu) or (hieu ve)) cham ((xuc va) OR (tuc va)) doanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach thu bang xa hoi. ((hieu vu) or (hieu ve)) cham ((xuc va) OR (tuc va)) doanh van cua tre*.