"For a solid approach to the complexity of Planck's intellectual motivations for the quantum, for his reluctant acceptance of its implications",Helge Kragh, Max Planck: the reluctant revolutionaryАрхивирано на сајту Wayback Machine (1. април 2012), Physics World,2000.
"For a solid approach to the complexity of Planck's intellectual motivations for the quantum, for his reluctant acceptance of its implications",Helge Kragh, Max Planck: the reluctant revolutionaryАрхивирано на сајту Wayback Machine (1. април 2012), Physics World,2000.
