Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nam thuc » nam thuoc, am thuc, nam thu
dang xay » dang van, van xay
vai cua » dai cua, hai cua, lai cua
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
va dan » va dao, va dau, va dap
ca dan » cac dan, ca dao

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 ty ((lang xa) or (dang xay)) hoi. hieu quang nam thuc ((va dan) OR (ca dan)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((lang xa) OR (dang xay)) hoi. hieu quang nam thuc ((va dan) OR (ca dan)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((lang xa) or (dang xay)) hoi. hieu quang nam thuc ((va dan) OR (ca dan)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((lang xa) or (dang xay)) hoi. hieu quang nam thuc ((va dan) OR (ca dan)) vai cua tre*.