Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
va doanh » van doanh, vay doanh, va danh
cau phuc » cau truc, chau phu, huu phuc
so sach » bo sach, co sach, hoc sach
cau luc » cau truc
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
so sanh » do sanh
y dang » ky dang, 2 dang, _ dang

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

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