Perhaps you should try some spelling variations:
dang xay » dang van, van xay
nam thuc » nam thuoc, am thuc, nam thu
thuc va » thuc vat, thuc dan, thuc day
qua nam » quan nam, cua nam, quang nam
su sach » so sach
lang xa » lang ha, lang van
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet
va dao » ca dao
dao vi » dao voi, dao ve, dao va
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (vu sach)) ty ((lang xa) or (dang xay)) hoi. hieu qua nam thuc va dao vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ty ((lang xa) OR (dang xay)) hoi. hieu qua nam thuc va dao vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ty ((lang xa) or (dang xay)) hoi. hieu qua nam thuc va dao vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ty ((lang xa) or (dang xay)) hoi. hieu qua nam thuc va dao vi cua tre*.