Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
nhan tai » hang tai, van tai, toan tai
hanh tai » thanh tai, hang tai, han tai
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
xuc ban » duc ban, cuc ban, quoc ban
cac xuc » cam xuc, cac nuoc, chat xuc
sach ky » sac ky, sach y, sach ty
nang ro » nang co, nang ho, nang ra
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang x

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 ((nang o) or (nang ro)) hai. hieu vien cac xuc ban ((hanh tai) or (nhan tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang o) OR (nang ro)) hai. hieu vien cac xuc ban ((hanh tai) OR (nhan tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang o) or (nang ro)) hai. hieu vien cac xuc ban ((hanh tai) or (nhan tai)) cua tre*.