Perhaps you should try some spelling variations:
ban hanh » ban hang
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
hanh ca » hanh cac, hanh cat, hanh cua
duc ban » duc tan, duc van, dua ban
ve cham » va cham, ve chat, vu cham
va cao » va cac, va co, va dao
ve cam » ve cac, va cam, ve cai
nang o » nang co, nang ho, nang ro
ca cua » co cua
cua te » cua tu
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 ky nang o hoi. hieu ((((ve cam) OR (ve cham))) or (va cao)) duc ban hanh ca cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hoi. hieu ((((ve cam) OR (ve cham))) OR (va cao)) duc ban hanh ca cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang o hoi. hieu ((((ve cam) OR (ve cham))) or (va cao)) duc ban hanh ca cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoi. hieu ((((ve cam) OR (ve cham))) or (va cao)) duc ban hanh ca cua te*.