the link to Birkhoff, G., & von Neumann, J. (1936). The logic of quantum mechanics. Annals of Mathematics, 823-843. is paywalled, but... https://ia800905.us.ar

the link to Birkhoff, G., & von Neumann, J. (1936). The logic of quantum mechanics. Annals of Mathematics, 823-843. is paywalled, but... https://ia800905.us.archive.org/21/items/TheLogicOfQuantumMechanics1936/the%20logic%20of%20quantum%20mechanics%201936.pdf https://ia800905.us.archive.org/21/items/TheLogicOfQuantumMe...