1. Bailes, M., Lyne, A. G. & Shemar, S. L. Nature 352, 311–313 (1991).
2. Bahcall, J. et al. The Decade of Discovery in Astronomy and Astrophysics (National Academy Press, Washington, DC, 1991).
3. Latham, D. W. et al. Nature 339, 38–40 (1989).
4. Cochran, W. D. Astrophys. J. Lett. (submitted).
5. Richard, D. W. et al. IAU Circ. No. 2178 (1969).