Perhaps you should try some spelling variations:
thanh hoai » thanh hoa, thanh oai, thanh hoang
thanh hai » thanh phan, thanh hoa, thanh san
so sach » so sanh, bo sach, co sach
duc van » duc va, duc tan, duc manh
sach tu » sach thu, cach tu, sach ty
van cau » van dau, van hau, van chat
van cam » van nam, van lam, van dam
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
cuu tre » cua tre, cau tren, cau treo

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