The latter proof is referenced, and upon checking the end notes, I found that it was published by one 'Lilly Hahn'.

Lilly, thought I, a woman? Sister to Hans? Getting excited I googled 'Lilly Hahn', and found one relevant hit, in the wikipedia article on Hans: 'He married in 1909 Eleonore ("Lilly") Hahn, and they had a baby, Nora'. That was all. So she was his wife, but... but...where did she come from? Where did she train? What else did she prove? So far, I can't find anything about her - no articles on Google scholar, no other mention of her work. How perfectly infuriating. This is not the only one. The history of mathematics (and science) is littered with such desaparecidas.
