How do I put more google adsense?

I'm using a blogger account right now and they let me pick only one type of google adsense. I've been on sites that have several different types of google adsense on the same page. How do they do that? And I've heard that there are restrictions in terms of how many of them you can put on your page?

 

you can put 3 block ads and 3 link units on a page. Of course, you can put also some referrals.