%0 Book Section %A Penrose, R. %A Isham, C. J. %B Quantum Concepts in Space and Time %D 1986 %E Penrose, Roger %E Isham, C. J. %I New York ;Oxford University Press %P 1 %T Quantum concepts in space and time. Proceedings of the Third Oxford Symposium on Quantum Gravity, held at Oxford, UK, March 1984