Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh hoi » thanh hoai, thanh hoa, thanh hai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
ky tang » ky dang, kho tang, ky trong
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet

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) or (hoc sinh)) ((ky nang) or (ky tang)) xa hoi. hieu van nam thuc vat thanh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sinh)) ((ky nang) OR (ky tang)) xa hoi. hieu van nam thuc vat thanh hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sinh)) ((ky nang) or (ky tang)) xa hoi. hieu van nam thuc vat thanh hoi cua tre*.