Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sach y, sach ty, sach kem
thu ban » thu hang
hanh de » hanh kem
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
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 (sac ky)) nang x hoi. hieu van nam thu ban ((hanh de) or (hanh ve)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. hieu van nam thu ban ((hanh de) OR (hanh ve)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang x hoi. hieu van nam thu ban ((hanh de) or (hanh ve)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang x hoi. hieu van nam thu ban ((hanh de) or (hanh ve)) cua tre*.