^Karl Kraus: Lorentzinvariante Gravitationstheorie, Dissertation, Freie Universität Berlin, 1962.
^Karl Kraus: Quantum Theory, Causality and EPR Experiments, in Proceedings of the Joensuu Symposium on the Foundations of Modern Physics: 50 Years of the EPR Gedankenexperiment, p. 138, World Scientific, Singapore, 1986.