Paul Keres is one of my all time favourite players. Part of the reason may be that I was given the second of his autobiographical games collections (The Middle Years Of Paul Keres) when I was a teenager. And I loved the fluency and clarity of his style.
Here’s a documentary about him which will serve as a taster. But I strongly recommend getting his original game collections (rather than the John Nunn edited versions) which are also available as a single volume which was published by Arco.