Bauer, F. E., Treister, E., Schawinski, K., Schulze, S., Luo, B., Alexander, D. M., …Yang, G. (2017). A new, faint population of X-ray transients. Monthly Notices of the Royal Astronomical Society, 467(4), 4841-4857. https://doi.org/10.1093/mnras/stx417