Perhaps you should try some spelling variations:
ban hanh » ban hang
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
su viet » so viet
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang cao hoi. hieu ve cac luc ((((ban hanh) or (va thanh))) or (va dan)) khoi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang cao hoi. hieu ve cac luc ((((ban hanh) OR (va thanh))) OR (va dan)) khoi su viet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang cao hoi. hieu ve cac luc ((((ban hanh) or (va thanh))) or (va dan)) khoi su viet*.