Perhaps you should try some spelling variations:
ban danh » ban doanh, ban dan, van danh
sang mai » sang ma, sang tai, lang mai
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
cua tre » cua te, cuu tre, cua triet
ban anh » ban banh, bang anh, van anh
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky sang mai hoi. hieu van cham duc ((((ban anh) OR (ban danh))) or (ban hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky sang mai hoi. hieu van cham duc ((((ban anh) OR (ban danh))) OR (ban hanh)) di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky sang mai hoi. hieu van cham duc ((((ban anh) OR (ban danh))) or (ban hanh)) di cua tre*".