Corcoran M.F., R. Petre, J.H. Swank, S.A. Drake, K. Koyama, Y. Tsuboi, R. Viotti, A. Damineli, K. Davidson, K. Ishibashi, and S. White, The Astrophysical Journal 494, 381-395 (1998).
Maran P., R.D. Robinson, S.N. Shore, J.W. Brosius, K.G. Carpenter, B.E. Woodgate, J.L. Linsky, A. Brown, P.B. Byrne, M.R. Kundu, and S. White, The Astrophysical Journal 421, 800 (1994).