Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dong
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
van cam » van nam, van lam, van cau
y nang » ky nang, ly nang, v nang
xuc va » tuc va, luc va, xac va
vi cua » vai cua, di cua
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: so sach ((y nang) or (van nang)) x hoi. hieu van cam ((xuc va) OR (duc va)) hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y nang) OR (van nang)) x hoi. hieu van cam ((xuc va) OR (duc va)) hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y nang) or (van nang)) x hoi. hieu van cam ((xuc va) OR (duc va)) hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) or (van nang)) x hoi. hieu van cam ((xuc va) OR (duc va)) hanh vi cua vat*.