Ages and metallicities of circumnuclear star formation regions from Gemini IFU observations O. L. Dors Jr., T. Storchi-Bergmann, R. A. Riffel and Alex. A. Schimdt A&A, 482 1 (2008) 59-65 Published online: 18 February 2008 DOI: 10.1051/0004-6361:20078960