Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh ca » thanh cha, thanh cac, thanh ha
so sach » so sanh, bo sach, co sach
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
duc ban » duc tan, duc van, dua ban
ca cua » co cua
cua te » cua tu
va cao » va cac, va co, va dao
ve cam » ve cham, ve cac, va cam
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu ((ve cam) or (va cao)) duc ban thanh ca cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang o hoi. hieu ((ve cam) OR (va cao)) duc ban thanh ca cua te.
• Adding a wildcard symbol may retrieve word variants: so sach ty nang o hoi. hieu ((ve cam) or (va cao)) duc ban thanh ca cua te*.