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 » ca viet, hoa viet, cua vat
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
tuc va » truc va, tuc xa, duc va
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) OR (thuc va)) hanh vai cua 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) OR (thuc va)) hanh vai cua viet~".
• Adding a wildcard symbol may retrieve word variants: so sach y nang ma hoi. ((hieu hien) or (dieu hien)) dai ((tuc va) OR (thuc va)) hanh vai cua viet*.