Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh doi » thanh loi, thanh moi, thanh do
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
sach ty » sach tu, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, dua tren
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ty) or (sach y)) nang xa hoi. hieu va nam thuc vat thanh doi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach y)) nang xa hoi. hieu va nam thuc vat thanh doi ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: toc ((sach ty) or (sach y)) nang xa hoi. hieu va nam thuc vat thanh doi ((cua tre) or (cua triet))*.