Perhaps you should try some spelling variations:
thanh hoai » thanh hoa, thanh hai, thanh oai
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
hoai cua » hoi cua, hoa cua, hai cua
nam thuc » nam thuoc, am thuc, nam thu
nam duc » nam duoc, pham duc, nam buoc
sach ty » sach y, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach uu
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: so ((sach ty) or (sach tu)) nang xa hoi. hieu van ((nam duc) or (nam thuc)) van thanh hoai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ty) OR (sach tu)) nang xa hoi. hieu van ((nam duc) OR (nam thuc)) van thanh hoai cua tre.
• Adding a wildcard symbol may retrieve word variants: so ((sach ty) or (sach tu)) nang xa hoi. hieu van ((nam duc) or (nam thuc)) van thanh hoai cua tre*.