Morris, S. L., Liebert, J., Stocke, J. T., Gioia, I. M., Schild, R. E., & Wolter, A. (1990). MS 1603.6 + 2600, an unusual X-ray selected binary system at high Galactic latitude. Astrophysical Journal, 365, 686-695. https://doi.org/10.1086/169523