Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
ve cham » va cham, vu cham, ve chim
ve chat » va chat, van chat
vu kham » vu khanh
va hanh » van hanh, va thanh, va danh
luc va » duc va, tuc va, loc va
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. hieu ((((ve cham) OR (ve chat))) or (vu kham)) luc va hanh vi va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. hieu ((((ve cham) OR (ve chat))) OR (vu kham)) luc va hanh vi va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang cao hoi. hieu ((((ve cham) OR (ve chat))) or (vu kham)) luc va hanh vi va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. hieu ((((ve cham) OR (ve chat))) or (vu kham)) luc va hanh vi va thiet*.