Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
cap nuoc » dat nuoc
va doanh » van doanh, vay doanh, va danh
sach lo » sach dao, sach doi, sach hoi
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
sach o » sac o, sach y, mach o

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

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