+# this file is part of refractiveindex.info database
+# refractiveindex.info database is in the public domain
+# copyright and related rights waived via CC0 1.0
+
+REFERENCES: "P. B. Johnson and R. W. Christy. Optical constants of the noble metals, <a href=\"https://doi.org/10.1103/PhysRevB.6.4370\"><i>Phys. Rev. B</i> <b>6</b>, 4370-4379 (1972)</a>"