Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
toc sach » hoc sach, doc sach, thuoc sach
va doanh » van doanh, vay doanh, va danh
van bao » van ban, van dao
van cua » vang cua, ban cua, dan cua
truc va » thuc va, thuc vat, trung va
van bac » van ban, van hac, dan bac
cua tre » cua te, cuu tre, cua triet
y lang » _ lang, tay lang, yen lang
o lang » hoa lang, hoi lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((y lang) OR (o lang)) xa hoi. hieu ((van bac) or (van bao)) truc va doanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y lang) OR (o lang)) xa hoi. hieu ((van bac) OR (van bao)) truc va doanh van cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y lang) OR (o lang)) xa hoi. hieu ((van bac) or (van bao)) truc va doanh van cua tre*".