Perhaps you should try some spelling variations:
thanh hoai » thanh hoa, thanh hai, thanh oai
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
van cam » van nam, van lam, van cau
cua tre » cuu tre, cua triet, dua tren
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
so sach » so sanh, bo sach, co 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 te » cua tu

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 ((nang xa) OR (nang ma)) hoi. hieu van cam duc ban thanh hoai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cam duc ban thanh hoai ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) OR (nang ma)) hoi. hieu van cam duc ban thanh hoai ((cua tre) or (cua te))*".