Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach y) or (sach tu)) nang ((x hoi) or (o hoi)). hieu va cam thuc va dan di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach y) OR (sach tu)) nang ((x hoi) OR (o hoi)). hieu va cam thuc va dan di cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach y) or (sach tu)) nang ((x hoi) or (o hoi)). hieu va cam thuc va dan di cua tre*.