Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
co loi » co hoi
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu
tu van » tu va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (vay khach)) ky nang ((co hoc) or (co loi)). hieu va cam tu van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vay khach)) ky nang ((co hoc) OR (co loi)). hieu va cam tu van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vay khach)) ky nang ((co hoc) or (co loi)). hieu va cam tu van hanh vi cua tre*.