Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
luc van » luoc van, luu van, duc van
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
va cao » va cac, va co, va dao
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu ((ve cam) or (va cao)) luc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ((ve cam) OR (va cao)) luc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ((ve cam) or (va cao)) luc van hanh vi cua tre*.