Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
va dauh » va danh, va doanh
van hoi » van hoa, van hoc, van hoe
hieu he » hieu ve, hiem he, hieu le
de cua » le cua, te cua, dieu cua
va dau » va dao
he nam » ha nam, nghe nam
y lang » _ lang, tay lang, yen lang
o lang » hoa lang, hoi lang
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 ((y lang) OR (o lang)) van hoi. hieu he nam thuc ((va dauh) or (va dau)) de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y lang) OR (o lang)) van hoi. hieu he nam thuc ((va dauh) OR (va dau)) de cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y lang) OR (o lang)) van hoi. hieu he nam thuc ((va dauh) or (va dau)) de cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ((y lang) OR (o lang)) van hoi. hieu he nam thuc ((va dauh) or (va dau)) de cua te*.