Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
dang xay » dang van, van xay
sach thu » sach thue, sach thieu, sach tham
nam thuc » nam thuoc, am thuc, nam thu
vai cua » dai cua, hai cua, lai cua
dao vai » dao van, dao va, dao bai
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, xach tay
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
va dao » 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: su ((sach ty) or (sach thu)) ((lang xa) or (dang xay)) hoi. hieu quang nam thuc va dao vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) ((lang xa) OR (dang xay)) hoi. hieu quang nam thuc va dao vai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) ((lang xa) or (dang xay)) hoi. hieu quang nam thuc va dao vai cua tre*.