Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
hoc can » hoc dan, hoc cao, hoc cac
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
vai va » mai va, dai va, hai va
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 ((tang ma) or (nang cao)) hoi. hieu ve cac ((duc va) or (hoc can)) hanh vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((tang ma) OR (nang cao)) hoi. hieu ve cac ((duc va) OR (hoc can)) hanh vai va triet.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((tang ma) or (nang cao)) hoi. hieu ve cac ((duc va) or (hoc can)) hanh vai va triet*.