Many of the descriptions of the various systems were taken from published introductory information provided by the system sponsors. We are grateful to A.C. Davenhall for providing us with his reviews prior to publication and for his careful reading of the manuscript. Many other people have contributed valuable information and suggestions, in alphabetical order: L. Benacchio, P. Boyce, L. Brotzman, E. Bryson, G. Dulk, G. Eichhorn, P. Giommi, D.E. Harris, J. Hayes, A. Heck, G. Helou, F. Hill, K. Long, R. Isaacman, B. Jackson, A. de Jonge, D. Kester, H.T. MacGillivray, M.-C. Marthinet, W.C. Martin, K. Nakajima, M. Nanni, F. Ochsenbein, H. Payne, B. Pirenne, A. Reynolds, M. Schmitz, F. Simien, K. Smale, P.L. Smith, S. Stevens-Rayburn, R.M. Shobbrook, C. Stern Grant, M. Van Steenberg, M. Vazquez, and M. Wenger. We thank the referees, E.D. Feigelson and D.R. Crabtree, as well as the Editor, H. Bond, for pointing out several other useful services to us. H.A. acknowledges a research grant of CNRS and is grateful for the hospitality he received at Instituto de Astrofí sica de Canarias and Observatoire de Lyon.