Perhaps you should try some spelling variations:
thanh hoa » thanh pho
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
sach tu » sach thu, cach tu, sach ty
cam duc » cam xuc, cao duc, nam duoc
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano

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 tu nang xa hoi. hieu van ((cam duc) OR (pham duc)) van thanh hoa ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tu nang xa hoi. hieu van ((cam duc) OR (pham duc)) van thanh hoa ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach tu nang xa hoi. hieu van ((cam duc) OR (pham duc)) van thanh hoa ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: so sach tu nang xa hoi. hieu van ((cam duc) OR (pham duc)) van thanh hoa ((cua tre) or (cuu tre))*.