Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
thai cua » than cua, tri cua, dai cua
te sach » toc sach
sach ky » sac ky, sach y, sach ty
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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