Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
ve cac » va cac, vien cac
lo van » le van, vo van, so van
x hoi » xa hoi, o hoi, x ho
lo va » lao va, ly va, le va

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 (vu sach)) ky nang x hoi. hieu ve cac ((lo va) OR (lo van)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang x hoi. hieu ve cac ((lo va) OR (lo van)) hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky nang x hoi. hieu ve cac ((lo va) OR (lo van)) hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky nang x hoi. hieu ve cac ((lo va) OR (lo van)) hanh vai cua tre*.