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