Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
thu nang » thi nang, thu hang, thu bang
tu sach » thu sach, su sach, te sach
van cua » vang cua, ban cua, dan cua
va cham » va chat, va tham
thu ban » thu hang
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
soc va » hoc va, doc va, goc va
loc va » hoc va, luc va

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 nang) or (thu ban)) xa hoi. hieu va cham ((soc va) OR (loc va)) doanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((thu nang) OR (thu ban)) xa hoi. hieu va cham ((soc va) OR (loc va)) doanh van cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((thu nang) or (thu ban)) xa hoi. hieu va cham ((soc va) OR (loc va)) doanh van cua tre*".