The M4 adaptive unit for the E-ELT B. Crépy, S. Chaillot, JM Conan, R. Cousty, C. Delrez, M. Dimmler, JL Dournaux, S. De Zotti, E. Gabriel, R. Gasmi et al. (13 more) Published online: 24 February 2010 DOI: 10.1051/ao4elt/201006001