Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
vu sach » vu bach, vu khach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
su sach » so sach
va cao » va cac, va co, va dao
ve cao » ve bao, ve cac, ve co

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