Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
hieu hien » bieu hien, chieu chien, dieu khien
cua viet » hoa viet, cua vat, cua dieu
hanh vai » hanh vi, hanh va, hanh tai
so sach » so sanh, bo sach, co sach
va hanh » van hanh, va thanh, va danh
dai tuc » dai thuc, dai truc, dao tuc
ca viet » va viet, co viet, hoa viet
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa

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 y nang ma hoi. ((hieu hien) OR (dieu hien)) dai tuc va hanh vai ((cua viet) OR (ca viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang ma hoi. ((hieu hien) or (dieu hien)) dai tuc va hanh vai ((cua viet) OR (ca viet))~".
• Adding a wildcard symbol may retrieve word variants: so sach y nang ma hoi. ((hieu hien) or (dieu hien)) dai tuc va hanh vai ((cua viet) OR (ca viet))*.