Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
v nang » va nang, van nang, voi nang
va tai » va tac, va tap
vi cua » vai cua, di cua

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: su sach ((v nang) OR (vu nang)) ma hoa. hieu va tai trung ((tuan anh) OR (va hanh)) vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) OR (vu nang)) ma hoa. hieu va tai trung ((tuan anh) or (va hanh)) vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) OR (vu nang)) ma hoa. hieu va tai trung ((tuan anh) or (va hanh)) vi cua viet*.