1. Harwit, M. Cosmic Discovery: The Search, Scope and Heritage of Astronomy (Basic Books, New York, 1981).
2. Angel, J. R. P. & Fugate, R. Q. Science 288, 455–456 (2000).
3. Tyson, J. A., Wittman, D. & Angel, J. R. P. in Gravitational Lensing: Recent Progress and Future Goals (eds Brainerd, T. & Kochanek, C.) ASP Conference Series (The Astronomical Society of the Pacific, in the press).
4. Angel, J. R. P., Cheng, A. Y. S. & Woolf, N. J. Nature 322, 341–343 (1986).
5. Angel, J. R. P., Burge, J., Hege, K., Kenworthy, M. & Woolf, N. J. Proc. SPIE 4013, 699–705 (2000).