1. Wheeler, J. A. in Mathematical Foundations of Quantum Mechanics (ed. Marlow, A. R.) 9–48 (Academic, New York, 1978).
2. Bohm, D. & Hiley, B. J. Fdn Phys. 14, 255–274 (1984).
3. Bell, J. S. in Quantum Gravity Vol. 2 (eds Isham, C. J., Penrose, R. & Sciama, D. W.) 611–637 (Clarendon, Oxford, 1980).
4. Bell, J. S. Int. J. Quant. Chem. Symp. 14, 155–159 (1980).
5. Bohr, N. in Quantum Theory and Measurement (eds Wheeler, J. A. & Zurek, W. H.) 30 (Princeton University Press, 1983).