BERNHARD, Christian, Todd HOLDEN, Alexandr BORIS, Natalia KOVALEVA, Alexei PIMENOV and
Josef HUMLÍČEK. Anomalous oxygen-isotope effect on the in-plane far-infrared conductivity of detwinned (YBa2Cu3O6.9)-O-16,18.
Physical Review B. USA: The American Physical Society, 2004, vol. 69, No 5, p. 2502-4, 4 pp. ISSN 0163-1829.