Ayres T.R., T. Simon, R.A. Stern, S.A. Drake, B.E. Wood, and A. Brown, The Astrophysical Journal 496, 428-448 (1998).
Hawley S.L., G.H. Fisher, T. Simon, S.L. Cully, S.E. Deustua, M. Jablonski, C.M. Johns-Krall, B.R. Pettersen, V. Smith, W.J. Spiesman, and J.A. Valenti, The Astrophysical Journal 453, 464 (1995).
and 
