Stephen Hawking 60th Birthday Workshop and Symposium Cambridge, England, Hawking, S. W., Gibbons, G. W., Shellard, E. P. S., & Rankin, S. J. (2003). The future of theoretical physics and cosmology: Celebrating Stephen Hawking's 60th birthday. Cambridge University Press.

Stephen Hawking 60th Birthday Workshop and Symposium Cambridge, England, S. W. Hawking, G. W. Gibbons, E. P. S. Shellard, and S. J. Rankin. The Future of Theoretical Physics and Cosmology: Celebrating Stephen Hawking's 60th Birthday. Cambridge, U.K: Cambridge University Press, 2003.

Stephen Hawking 60th Birthday Workshop and Symposium Cambridge, England, et al. The Future of Theoretical Physics and Cosmology: Celebrating Stephen Hawking's 60th Birthday. Cambridge University Press, 2003.