Perhaps you should try some spelling variations:
doanh gia » doanh giao, doanh giai, danh gia
sach tham » sach nha
sach thu » sach thue, sach thieu, cach thuc
gia cua » gian cua, giau cua, gia cuc
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
mang xa » lang xa, mang may, dang xay
va cam » va cham, va cac, va cao
lo va » lo van, lao va, le 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) OR (sach tham)) mang xa hoi. hieu va cam ((lo va) or (ly va)) doanh gia cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sach tham)) mang xa hoi. hieu va cam ((lo va) OR (ly va)) doanh gia cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach thu) OR (sach tham)) mang xa hoi. hieu va cam ((lo va) or (ly va)) doanh gia cua tre*".