Perhaps you should try some spelling variations:
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
hoc can » hoc dan, hoc cao, hoc cac
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
di cuu » di cau, di cua, dinh cuu

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 sang ma hoi. hieu ve cac ((duc tan) or (hoc can)) hanh di cuu tre~.
• 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 di cuu tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky sang ma hoi. hieu ve cac ((duc tan) or (hoc can)) hanh di cuu tre*.