Abbott, B.P.., R.. Abbott, T.D.. Abbott, M.R.. Abernathy, F.. Acernese, K.. Ackley, C.. Adams, T.. Adams, P.. Addesso, R.X.. Adhikari, et al.,
"Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run",
Physical Review Letters, vol. 118, no. 12, 2017.