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
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
xuc van » luc van, xuc ban, thuc van
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi
va va » va van, va vua, va vai
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 chat ((xuc van) or (duc van)) hanh va va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. hieu ve chat ((xuc van) OR (duc van)) hanh va va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. hieu ve chat ((xuc van) or (duc van)) hanh va va thiet*.