Keywords: Kronig.jpg Ralph Kronig Leiden 1924 cropped from Image ehrenfeststudents jpg http //www lorentz leidenuniv nl/history/spin/ehrenfeststudents jpg Photo by Paul Ehrenfest's 1880-1933 designee PD-old Original upload log page en wikipedia Kronig jpg 2005-12-03 14 18 Voyajer 800×1008× 44328 bytes <nowiki></nowiki> 2005-12-03 13 53 Voyajer 800×1008× 44328 bytes <nowiki>http //www exafsco com/techpapers/graphics/Kronig jpg Permissions for public domain download http //www exafsco com/techpapers/Printing html http //www exafsco com/techpapers/</nowiki> Ralph Kronig Photos by Paul Ehrenfest |