Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
bach ky » bac ky
dai xuc » dai xu, dai luoc, dai thuc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » o hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky nang ((x hoi) OR (xa hoi)). hieu vien dai xuc ((va hanh) or (gia thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky nang ((x hoi) OR (xa hoi)). hieu vien dai xuc ((va hanh) OR (gia thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky nang ((x hoi) OR (xa hoi)). hieu vien dai xuc ((va hanh) or (gia thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu bach ky nang ((x hoi) OR (xa hoi)). hieu vien dai xuc ((va hanh) or (gia thanh)) vi cua tre*.