3π and 4π meson production in np interactions at intermediate energies A.P. Jerusalimov, A.V. Belyaev, V.P. Ladygin, V.N. Pechenov and Yu.A. Troyan EPJ Web Conf., 138 (2017) 07008 Published online: 27 March 2017 DOI: 10.1051/epjconf/201713807008