Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, cao hoc, tao hoi
ve cham » va cham, ve chat, vu cham
vu kham » vu khanh
xuc van » duc van, luc van, vuc van
co hoi » co hoc, co loi
vi va » vi van, vai va, vu va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((cao hoi) or (co hoi)). hieu ((ve cham) or (vu kham)) xuc van hanh vi va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((cao hoi) OR (co hoi)). hieu ((ve cham) OR (vu kham)) xuc van hanh vi va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((cao hoi) or (co hoi)). hieu ((ve cham) or (vu kham)) xuc van hanh vi va thiet*.