Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
hieu ve » hieu va, hieu van
hoc can » hoc dan, hoc cao, hoc cac
vai va » mai va, dai va, hai va
te sai » te tai, te bai, te lai
sai ky » sac ky
ma hoi » mai hoi, ma hoa, me hoi
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 sai ky nang ((ma hoi) or (xa 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 sai ky nang ((ma hoi) OR (xa hoi)). hieu ve cac ((duc va) OR (hoc can)) hanh vai va triet.
• Adding a wildcard symbol may retrieve word variants: te sai ky nang ((ma hoi) or (xa hoi)). hieu ve cac ((duc va) or (hoc can)) hanh vai va triet*.