Bukhtiyarov, V. I., Hävecker, M., Kaichev, V. V., Knop-Gericke, A., Mayer, R. W., & Schlögl, R. (2003). The nature of atomic oxygen species on silver: photoelectron spectroscopy and x-ray absorption studies. Physical Review B, 67(23): 235422. doi:10.1103/PhysRevB.67.235422.