Perhaps you should try some spelling variations:
dinh lam » dinh van, tinh lao
dinh dai » dinh dat, sinh dai, dinh dao
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
vu sai » vu hai, vu san, vu dai
sai ky » sac ky
cac tu » cac thu, cach tu, tac tu
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: vu sai ky tang ma hoi. hieu qua ((cac tu) OR (cac du)) va ((dinh dai) OR (dinh lam)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sai ky tang ma hoi. hieu qua ((cac tu) OR (cac du)) va ((dinh dai) or (dinh lam)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: vu sai ky tang ma hoi. hieu qua ((cac tu) OR (cac du)) va ((dinh dai) or (dinh lam)) cua tre*.