Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dau thau » dau tu
cuu tre » cau tren, cau treo
cac toc » cac toi, cac nuoc, cac thoi
van cac » van hac, van cau, van bac
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach ty, sach kem
toc va » hoc va, toc ta, tuc va
va dau » va dao
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: tu ((sach ky) or (sach y)) nang x hoi. hieu van cac toc va dau thau ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang x hoi. hieu van cac toc va dau thau ((cuu tre) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang x hoi. hieu van cac toc va dau thau ((cuu tre) or (cua tre))*.