Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
co hoi » co loi

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: tu ((sach ky) OR (sach ty)) nang ((co hoi) OR (co hoc)). hieu vien cac xuc van hanh thai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang ((co hoi) or (co hoc)). hieu vien cac xuc van hanh thai cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang ((co hoi) or (co hoc)). hieu vien cac xuc van hanh thai cua tre*.