Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
cac xuc » cam xuc, cac nuoc, chat xuc
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, ma hoa, me hoi
xuc va » duc va, tuc va, luc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang ((ma hoi) or (xa hoi)). hieu vien cac xuc va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ((ma hoi) OR (xa hoi)). hieu vien cac xuc va hanh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ((ma hoi) or (xa hoi)). hieu vien cac xuc va hanh lai cua tre*.