Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
nam thuc » nam thuoc, am thuc, nam thu
quan nam » quang nam, xuan nam, quan am
tai cua » thai cua, tai cuc, tri cua
va dung » van dung, va duong, vat dung
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
sach ty » sach tu, sach thu, xach tay
nang xa » lang xa, nang ma, mang xa

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 y)) ((nang xa) or (nang x)) hoi. hieu quan nam thuc va dung tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) ((nang xa) OR (nang x)) hoi. hieu quan nam thuc va dung tai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) ((nang xa) or (nang x)) hoi. hieu quan nam thuc va dung tai cua tre*.