Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
hanh vai » hanh vi, hanh va, hanh tai
nien cac » dien cac, bien cac, hien cac
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
co va » co ma, do va, so va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (so sach)) ky nang x ho. thieu ((nien cac) OR (vien cac)) co va hanh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (so sach)) ky nang x ho. thieu ((nien cac) OR (vien cac)) co va hanh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (so sach)) ky nang x ho. thieu ((nien cac) OR (vien cac)) co va hanh vai cua tre*.