Multi-generation massive star-formation in NGC 3576 C. R. Purcell, V. Minier, S. N. Longmore, Ph. André, A. J. Walsh, P. Jones, F. Herpin, T. Hill, M. R. Cunningham and M. G. Burton A&A, 504 1 (2009) 139-159 Published online: 09 July 2009 DOI: 10.1051/0004-6361/200811358