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
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
tu sach » thu sach, su sach, tu cach
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
co loi » co hoi
o hoc » co hoc, mo hoc, so hoc

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