Books for intermediate/advance students Most of the books about Buddhism I can find were made for Beginners, most are very good and touch the key points, easy to find and to buy.

The problem is that after a while I started to look for more advanced books, made for people that have already studied the key principles of the Dhamma and wanna take one step further, this is very hard to find!

Anyone can indicate a book about Buddhism (suttas, Abidhamma, techniques etc.) More suitable for advance students?
What particular subject would you like to study? Just comment on this answer with a list of subjects you want to learn and I will put together a list for you and edit it in this comment.

Would you like to focus on a particular tradition within Theravada? (I'm assuming you're asking about Theravada because you are using Pali terms.)