Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, van thanh
ban thanh » ban hanh, ban hang
hieu van » thien van, lieu va, hieu ve
lam thuc » lam thuoc, am thuc, nam thuc
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
sach v » sach va, sach y, sach 2
v lang » va lang, o lang, _ lang
cua tu » cua tuc, cua su, cua cu

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 v lang xa hoi. ((hieu van) OR (hieu va)) lam thuc ((dan thanh) or (ban thanh)) dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v lang xa hoi. ((hieu van) OR (hieu va)) lam thuc ((dan thanh) OR (ban thanh)) dai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v lang xa hoi. ((hieu van) OR (hieu va)) lam thuc ((dan thanh) or (ban thanh)) dai cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach v lang xa hoi. ((hieu van) OR (hieu va)) lam thuc ((dan thanh) or (ban thanh)) dai cua tu*.