Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
xuc van » duc van, luc van, xuc ban
cua tre » cua te, cuu tre, cua triet
cao hoi » cau hoi, co hoi, cao hoc
bo sach » co sach, hoc sach
ve cac » va cac, vien cac
vi cua » vai cua, di cua
ve cam » ve cham, va cam, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (bo sach)) ky nang cao hoi. hieu ((ve cam) or (ve cac)) xuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (bo sach)) ky nang cao hoi. hieu ((ve cam) OR (ve cac)) xuc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (bo sach)) ky nang cao hoi. hieu ((ve cam) or (ve cac)) xuc van hanh vi cua tre*.