Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam tu
dang xay » dang van, van xay
sach tay » xach tay, sach hay, sach nay
so sach » so sanh, bo sach, co sach
lang de » vang de, dang de, lang du
va lang » va nang, hoa lang
hieu ve » hieu va, hieu van
lang xa » lang ha, lang van
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 tay ((lang xa) OR (dang xay)) hoi. hieu ve ((nam thuc) or (nam thu)) va lang de cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tay ((lang xa) OR (dang xay)) hoi. hieu ve ((nam thuc) OR (nam thu)) va lang de cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tay ((lang xa) OR (dang xay)) hoi. hieu ve ((nam thuc) or (nam thu)) va lang de cua te".
• Adding a wildcard symbol may retrieve word variants: so sach tay ((lang xa) OR (dang xay)) hoi. hieu ve ((nam thuc) or (nam thu)) va lang de cua te*.