Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
van thanh » ban thanh, van tuan
so sach » bo sach, co sach, hoc sach
van lam » van nam
hoi cua » hoi chuc
duc van » duc va, duc tan, duc manh
van cam » van nam, van cau, van dam
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
so sanh » do sanh
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) OR (so sanh)) tu nang xa hoi. hieu ((van cam) or (van lam)) duc van thanh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) tu nang xa hoi. hieu ((van cam) OR (van lam)) duc van thanh hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (so sanh)) tu nang xa hoi. hieu ((van cam) or (van lam)) duc van thanh hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (so sanh)) tu nang xa hoi. hieu ((van cam) or (van lam)) duc van thanh hoi cua tre*.