Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
va nang » van nang, da nang, cam nang
van cau » van dau, van hau, van chat
cau tuc » cau truc, cau tu, cau luc
kem cua » em cua, keo cua, diem cua
tu sach » thu sach, su sach, te sach
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dap
va dau » va dao

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 ((y nang) OR (va nang)) ma hoi. hieu van cau tuc ((va dan) OR (va dau)) kem cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) or (va nang)) ma hoi. hieu van cau tuc ((va dan) OR (va dau)) kem cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (va nang)) ma hoi. hieu van cau tuc ((va dan) OR (va dau)) kem cua viet*.