Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
hieu van » hieu va, thien van, lieu va
sach ty » sach tu, sach thu, xach tay
lang xa » lang ha, dang xay, lang van
van lam » van nam
duoc va » nuoc va, duoc ma, duong va
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) OR (sach y)) lang xa hoi. hieu van lam ((duoc va) or (duc va)) doanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach y)) lang xa hoi. hieu van lam ((duoc va) OR (duc va)) doanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach y)) lang xa hoi. hieu van lam ((duoc va) or (duc va)) doanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) OR (sach y)) lang xa hoi. hieu van lam ((duoc va) or (duc va)) doanh van cua tre*.