Perhaps you should try some spelling variations:
luoc can » luc canh, hoc can, luoc dai
hanh vai » hanh vi, hanh va, hanh tai
cua tre » cua te, cuu tre, cua triet
ky hang » ky nang, ly hang, ky dang
tai hoi » tai khoi, dai hoi, tai hai
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
tai ha » thai ha, tai hai, tai nha
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky hang ((tai hoi) or (tai ha)). hieu ve cac ((duc va) or (luoc can)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky hang ((tai hoi) OR (tai ha)). hieu ve cac ((duc va) OR (luoc can)) hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky hang ((tai hoi) or (tai ha)). hieu ve cac ((duc va) or (luoc can)) hanh vai cua tre*.