Perhaps you should try some spelling variations:
luoc can » luc canh, hoc can, luoc dai
lang mai » lang dai, lang hai, lang man
vai cua » dai cua, hai cua, lai cua
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
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 hoi. hieu ve cac ((duc van) or (luoc can)) hanh ((vai cuu) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky lang mai hoi. hieu ve cac ((duc van) OR (luoc can)) hanh ((vai cuu) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky lang mai hoi. hieu ve cac ((duc van) or (luoc can)) hanh ((vai cuu) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky lang mai hoi. hieu ve cac ((duc van) or (luoc can)) hanh ((vai cuu) OR (vai cua)) tre*.