Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
hanh thai » nhanh thai, hinh thai, hanh tai
vien cac » vien bach, vien dai, vien da
thai cua » than cua, tai cuc, tri cua
duc van » duc va, duc tan, duc manh
xuc van » luc van, vuc van, xuc ban
te sach » toc sach
sach ky » sac ky, sach y, sach ty
tang ho » tang cho, tung ho, tang ha
nang ho » nang hoc, nang co, nang cao
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang ho) OR (tang ho)) hai. hieu vien cac ((xuc van) or (duc van)) hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ho) OR (tang ho)) hai. hieu vien cac ((xuc van) OR (duc van)) hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang ho) OR (tang ho)) hai. hieu vien cac ((xuc van) or (duc van)) hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ho) OR (tang ho)) hai. hieu vien cac ((xuc van) or (duc van)) hanh thai cua tre*.