Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
cua tre » cua te, cuu tre, cua triet
lai cua » dai cua, hai cua, lai chau
va daoh » va danh, va doanh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
ky sang » ky nang, ky dang, ky tang
mai hoi » dai hoi, lai hoi, mai doi
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
va dao » ca dao
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky sang ((mai hoi) OR (mai khoi)). hieu ve cac duc ((va daoh) or (va dao)) lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky sang ((mai hoi) OR (mai khoi)). hieu ve cac duc ((va daoh) OR (va dao)) lai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky sang ((mai hoi) OR (mai khoi)). hieu ve cac duc ((va daoh) or (va dao)) lai cua tre*".