Feeds from one blog to another

Hi

I am wandering if this is possible and how I would go about doing it.

I have blogs a, b & c. If I post an article on B and another article on C, is there a way or having some kind of post on A on each respective article, as soon as I publish on B or C, it will show up on A? In theroy, the begining of each article will show up on A, and to read the full article, it will take you to either of the 2 blogs?

Its a bit random, but ….

Any ideas or codex links which explain what I am trying to do?

Thank you