Perhaps you should try some spelling variations:
van thiet » va thiet, dan thiet, can thiet
hieu van » hieu va, thien van, lieu va
van chat » cao chat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi

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