Perhaps you should try some spelling variations:
ban hang » ngan hang
va triet » va thiet, va trien, ve triet
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
cac thu » cach thuc, cac thoi

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 xa hoi. hieu ve ((cac thu) or (am thuc)) ban hang va ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. hieu ve ((cac thu) OR (am thuc)) ban hang va ((va triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. hieu ve ((cac thu) or (am thuc)) ban hang va ((va triet) or (su triet))*.