First Results from NuSTAR Observations of Mkn 421 M. Baloković, M. Ajello, R. D. Blandford, S. E. Boggs, F. Borracci, J. Chiang, F. E. Christensen, W. W. Craig, K. Forster, A. Furniss et al. (27 more) EPJ Web of Conferences, 61 (2013) 04013 Published online: 09 December 2013 DOI: 10.1051/epjconf/20136104013