Would be interesting if I could read it

Quantum physics: The quantum atom 

This special issue of Nature explores the origin and legacy of Bohr's quantum atom, a model that has resonated ever since. In 1911, Bohr began a postdoctoral year in England that planted the seeds of his thinking. In a Comment on page 27, historian John Heilbron relates how letters from Bohr to his brother Harald and to his fiancée, Margrethe Nørlund, published this year, chart the dauntless physicist's work with J. J. Thomson and Ernest Rutherford, and his study of the papers of John William Nicholson, which presaged his breakthrough.

All stuck behind the ridiculously expensive Nature paywall, unfortunately.   Seriously, who is going to pay £12 for access to an article like that?