1 B.. Boroson, R.A. McCray, C.O. Clark, J.D. Slavin, M.-M.M. Low, Y.-H.. Chu, and D.. Van Buren, The Astrophysical Journal 478, (1997).
1 D.. Van Buren, M.-M.M. Low, D.O.S. Wood, and E.B. Churchwell, The Astrophysical Journal 353, (1990).