Figured Bass

I recommend you

Federico Dal Sordo: "Il basso continuo"

He offers excellent citations and explanations of the most important treatises from all schools, along with exercises accompanied by examples. It is very expensive but worth it

There are also historical texts like those of Keller and Christensen, the latter only dealing with the French and German schools in the 18th century

Apart from what has already been said, excellent reports... I'll pass you a couple of truly useful links

http://www.lysator.liu.se/~tuben/scores/

Too bad about this one, I just discovered that it is temporarily "out of use"

http://www.bassus-generalis.org/

Thank you all

Ludovica wrote:

There are also historical topics

I was looking for something modern that would best synthesize the basic concepts in understandable Italian.

...more recent than this...

http://www.hoepli.it/libro/il-basso-continuo-/9788895738024.html

It's also obvious