Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
dung cua » dung luan, dung cho
dung mo » dung co, dung cho
tuc vat » thuc vat, tuc va, tuc hat
cac tuc » cac toc, cac tu, cac tac
qua cac » cua cac
cua tre » cua te, cuu tre, cua triet
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: su ((sach thu) or (sach y)) nang x hoi. hieu qua cac tuc vat ((dung mo) or (dung cua)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach thu) OR (sach y)) nang x hoi. hieu qua cac tuc vat ((dung mo) OR (dung cua)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach thu) or (sach y)) nang x hoi. hieu qua cac tuc vat ((dung mo) or (dung cua)) cua tre*.