Perhaps you should try some spelling variations:
sach nay » sach hay, sach vay, sach nang
nay lang » nam lang, tay lang, nhan lang
nam thue » nam thu, nam thuc, lam thue
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
thue va » thuc va, thuyet va, thuc vat
va dang » van dang, va nang, va lang
dang de » dang deo, dung de, dang do
ve nam » he nam, va nam, le nam
de cua » le cua, te cua, dieu cua
cua te » cua tu

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 nay lang ((xa hoi) or (ha noi)). hieu ve nam thue va dang de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach nay lang ((xa hoi) OR (ha noi)). hieu ve nam thue va dang de cua te.
• Adding a wildcard symbol may retrieve word variants: so sach nay lang ((xa hoi) or (ha noi)). hieu ve nam thue va dang de cua te*.