1. Allen, D.A., and Sanders, R.H., Nature, 319, 191, 1986.
2. Allen, D.A., Hyland, A.R., and Hillier, D.J., IAU Symposium No 136: The Galactic
Center, 1988.
3. Becklin, E.E and Neugebauer, G., Ap. J. (Letters), 200, L71, 1975.
4. De Poy, D.L., Gatley, I., and McLean, I., IAU Symposium No 136: The Galactic
Center, 1988.
5. Forrest, W.J., Shure, M.A., Pipher, J.L., and Woodward, C.E., in AIP Conference Proceedings 155, The Galactic Center, ed. D.C. Becker, p.153, 1987.