Perhaps you should try some spelling variations:
luoc can » luc canh, hoc can, luoc dai
lang mai » lang dai, lang hai, lang man
mai khoi » mai khoa, tai khoa, cac khoi
su triet » su tien, ve triet
su viet » so viet
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
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 lang mai khoi. hieu ve cac ((duc van) or (luoc can)) hanh vi ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky lang mai khoi. hieu ve cac ((duc van) OR (luoc can)) hanh vi ((su triet) OR (su viet)).
• Adding a wildcard symbol may retrieve word variants: te sac ky lang mai khoi. hieu ve cac ((duc van) or (luoc can)) hanh vi ((su triet) or (su viet))*.