Cosmic ray induced ionisation of a molecular cloud shocked by the W28 supernova remnant S. Vaupré, P. Hily-Blant, C. Ceccarelli, G. Dubus, S. Gabici and T. Montmerle A&A, 568 (2014) A50 Published online: 13 August 2014 DOI: 10.1051/0004-6361/201424036