Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
thanh di » thanh doi, thanh de, thanh do
te sach » toc sach
duc ban » duc tan, duc van, dua ban
hoc duc » hoc duoc, hoc nuoc, hoc thuc
sach ky » sac ky, sach y, sach ty
van hoc » van hoa
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ma) OR (tang ma)) hoi. hieu van hoc duc ban thanh di ((cua tu) OR (cua cu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang ma) or (tang ma)) hoi. hieu van hoc duc ban thanh di ((cua tu) OR (cua cu))~".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ma) or (tang ma)) hoi. hieu van hoc duc ban thanh di ((cua tu) OR (cua cu))*.