Perhaps you should try some spelling variations:
hoc can » hoc dan, hoc cao, hoc cac
hieu ve » hieu va, hieu van
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
vi cua » vai cua
di cua » dai cua, doi cua, de cua
te sac » te sach, te cac, te san

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang ma hoi. hieu ve cac ((duc tan) OR (hoc can)) hanh ((vi cua) OR (di cua)) tre~.
• Adding a wildcard symbol may retrieve word variants: te sac ky sang ma hoi. hieu ve cac ((duc tan) or (hoc can)) hanh ((vi cua) or (di cua)) tre*.