Mathematicians work a lot and are usually inspired by many things. In their lifetimes they get to publish only portions of their results. There have been stories of how Gauss, Euler, Ramanujan, Einstein, Hilbert etc kept notebooks and in it we can find glimpses to their thought processes and glimpses to results they did not publish and nevertheless would have turned to be important if in fact they had done. These are known classical examples.


1. Are there notable example of recent mathematicians who kept such notebooks?
2. I find lot of mathematicians have blogs but these are on published results. Do mathematicians still have such notebooks and if so when do they transfer their results usually to their notebooks and when do they transfer such results to publication (in other words I am asking for organizing principles for organizing thought processes and progress)?



Do mathematicians use notebooks to keep their results these days?
1. Yes, mathematicians keep notebooks. Sometimes, after their death, notebooks are published.
Here is an example: <http://www.claymath.org/publications/quillen-notebooks>


Here is another example, though not so recent: <https://www.math.uu.se/collaboration/beurling/unpublished-manuscripts/>


I believe many mathematicians have a lot of unpublished stuff. Sometimes their friends and students publish this after their death, exactly as it happened in the past.


2. Mathematicians discuss on their blogs and web pages not only published results. There are many examples. Much material exists in the form of correspondence, lecture notes, and preprints which are not officially made public (not available to everyone, like blogs) and which mathematicians share among their colleagues.


