Well, he was a student of Hegel's and described his work own work as "turning Hegel on his head". As for the other two it's conceivable these influences may have been formative during his student years.

I love Hegel. Get his complete works and keyword search!

I wish I could better understand dialectic materialism in order to critique it. I can't get around not having a noetic reality that serves like chaotic attractors to materials. Spheres and triangles are just more real than material manifestations. Penrose and Popper proposed similar tripartite realities of, roughly, the material, the conscious and the mathematical.

Indeed, Platonism seems to be a useful mental framework, and separating the three realities from each other helps to keep some degree of sanity when thinking about all these things.