Perhaps you should try some spelling variations:
than soc » than hoc, than so, thanh son
ban hang » ngan hang
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
ma hoi » mai hoi, xa hoi, ma hoa
va cua » va chua, via cua, ca cua

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 cac ky tang ma hoi. hieu qua ((than soc) OR (than doc)) ban hang va cua tre~.
• Adding a wildcard symbol may retrieve word variants: te cac ky tang ma hoi. hieu qua ((than soc) or (than doc)) ban hang va cua tre*.