Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, hoc sach
co sach » bo sach, cuon sach, hoc sach
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
hang di » hang doi, hang dien, hang dich
hang vi » hang va, hanh vi, khang voi
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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: ((so sach) OR (co sach)) y nang x hoi. hieu va cac tuc van ((hang di) OR (hang vi)) cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (co sach)) y nang x hoi. hieu va cac tuc van ((hang di) or (hang vi)) cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (co sach)) y nang x hoi. hieu va cac tuc van ((hang di) or (hang vi)) cua viet*.