Perhaps you should try some spelling variations:
van thiet » va thiet, dan thiet, can thiet
dinh tu » danh tu, dinh cu, tinh tu
xuc ban » duc ban, cuc ban, quoc ban
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty hang, ly nang
va cam » va cham, va cac, va cao
tu van » tu va
x hoi » xa hoi, o hoi, x ho

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 ((ty nang) or (ty xang)) x hoi. hieu va cam ((xuc van) or (xuc ban)) dinh tu van thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) x hoi. hieu va cam ((xuc van) OR (xuc ban)) dinh tu van thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) x hoi. hieu va cam ((xuc van) or (xuc ban)) dinh tu van thiet*.