Cash W.C., P. Charles, S. Bowyer, F.M. Walter, T.R. Ayres, and J.L. Linsky, The Astrophysical Journal 231, L137 (1979).
Linsky J.L., T.R. Ayres, G.S. Basri, N.D. Morrison, A. Boggess, F.H. Schiffer, A.V. Holm, A. Cassatella, A. Heck, F. Macchetto, and D.J. Stickland, Nature 275, 389-394 (1978).
Ayres T.R., J.L. Linsky, and N.D. Morrison, Bulletin Of The American Astronomical Society 10, (1978).