Perhaps you should try some spelling variations:
cua tre » cua te, cuu tre, cua triet
hoc can » hoc dan, hoc cao, hoc cac
ky dang » ky nang, ky danh
tao hoi » tao khoi, tay hoi, thao hoc
hanh di » hanh vi, hanh de, hang di
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc manh
di cua » dai cua, doi cua, de cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
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 dang ((tao hoi) or (tao boi)). hieu ve cac ((duc van) or (hoc can)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang ((tao hoi) OR (tao boi)). hieu ve cac ((duc van) OR (hoc can)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky dang ((tao hoi) or (tao boi)). hieu ve cac ((duc van) or (hoc can)) hanh di cua tre*.