(John von Neumann) “Representations and ray-representations in quantum mechanics”. 250-word abstract from the Pittsburgh Symposium on Group theory and Quantum Mechanics, published in the Bulletin of the American Mathematical Society, volume XLI, number 5, May 1935, page 350. Offered is the entire issue pp 305-352, in the original printed wrappers.
Very Good copy. $75
See:
Muraskin Murray, Brody F, Vamos Tibor, editors, The Neumann Compendium, appendix 2 (abstracts presented to the AMS), p 680 and p 49 #4 of bibliography.
Hans Primas, Knowledge and Time, p 402