The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environmentF. Grisé, M. W. Pakull, R. Soria, C. Motch, I. A. Smith, S. D. Ryder and M. BöttcherA&A, 486 1 (2008) 151-163DOI: https://doi.org/10.1051/0004-6361:200809557