Perhaps you should try some spelling variations:
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
hanh di » hanh vi, hanh de, hang di
hieu ve » hieu va, hieu van
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
ma hoi » xa hoi, ma hoa, me hoi
di cua » dai cua, doi cua, de cua
te sac » te sach, te cac, te san

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 sang ((ma hoi) OR (mai hoi)). hieu ve cac ((duc tan) or (hoc dan)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang ((ma hoi) OR (mai hoi)). hieu ve cac ((duc tan) OR (hoc dan)) hanh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky sang ((ma hoi) OR (mai hoi)). hieu ve cac ((duc tan) or (hoc dan)) hanh di cua tre*".