Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
danh vai » danh sai, danh va, doanh van
vien cac » vien bach, vien dai, vien da
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
cac lao » ca lao, cac loai, cac giao
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
lao va » tao va, cao va, bao va
o hoi » co hoi, o hoc, o hai
x hoi » xa 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: ((tu sach) or (su sach)) ky nang ((x hoi) OR (o hoi)). hieu vien cac lao va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ((x hoi) OR (o hoi)). hieu vien cac lao va danh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang ((x hoi) OR (o hoi)). hieu vien cac lao va danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang ((x hoi) OR (o hoi)). hieu vien cac lao va danh vai cua tre*.