1 N.. St-Louis, L.J. Smith, I.R. Stevens, A.J. Willis, C.D. Garmany, and P.S. Conti, Astronomy and Astrophysics 226, (1989).
1 I.R. Stevens, M.F. Corcoran, A.J. Willis, S.L. Skinner, A.M.T. Pollock, F.. Nagase, and K.. Koyama, Monthly Notices of the Royal Astronomical Society 283, (1996).