A search for Fermi bursts associated with supernovae and their frequency of occurrence M. Kovacevic, L. Izzo, Y. Wang, M. Muccino, M. Della Valle, L. Amati, C. Barbarino, M. Enderli, G. B. Pisani and L. Li A&A, 569 (2014) A108 Published online: 30 September 2014 DOI: 10.1051/0004-6361/201424700