Chemical composition of UV-bright star ZNG 4 in the globular cluster M 13 S. Ambika, M. Parthasarathy, W. Aoki, T. Fujii, Y. Nakada, Y. Ita and H. Izumiura A&A, 417 1 (2004) 293-300 Published online: 16 March 2004 DOI: 10.1051/0004-6361:20031759