Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty hang, ly nang
van cau » van dau, van hau, van chat
xuc va » duc va, tuc va, luc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) x ho. hieu van cau ((xuc va) OR (tuc xa)) hanh dai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty xang)) x ho. hieu van cau ((xuc va) or (tuc xa)) hanh dai cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty xang)) x ho. hieu van cau ((xuc va) or (tuc xa)) hanh dai cua viet*.