@article{Farhi1989HowPA,
title={How probability arises in quantum mechanics},
author={E. Farhi and J. Goldstone and S. Gutmann},
journal={Annals of Physics},
year={1989},
volume={192},
pages={368-382}
}

Abstract A version of the postulates of quantum mechanics is presented in which no reference is made to probability. Instead we rely on a weaker postulate referring to eigenvalues and eigenstates. The modulus squared of the inner product of two state vectors is shown to be an eigenvalue of the operator representing a frequency measurement on the system of an infinite number of copies of the original system. The argument makes essential use of the Strong Law of Large Numbers.