Perhaps you should try some spelling variations:
sach thame » sach thue
sach tham » sach nha
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
dan dai » dat dai, can dai, dan dat
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
x hoi » xa hoi, o hoi, x ho

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

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