Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
cua viet » ca viet, hoa viet, cua vat
va hanh » van hanh, va thanh, va danh
dai tuc » dai thuc, dai truc, dao tuc
so sach » bo sach, co sach, hoc sach
nang ma » sang ma, nang cao, mang may
so sanh » do sanh
tang ma » mang may, tang van
tuc va » thuc va, truc va, tuc xa
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: ((so sach) OR (so sanh)) y ((nang ma) OR (tang ma)) hoi. hieu hien dai tuc va hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) y ((nang ma) OR (tang ma)) hoi. hieu hien dai tuc va hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) y ((nang ma) OR (tang ma)) hoi. hieu hien dai tuc va hanh vi cua viet*.