Negative refraction of a three-dimensional metallic photonic crystal A. Mahmoudi, A. Semnani, R. Alizadeh and R. Adeli Eur. Phys. J. Appl. Phys., 39 1 (2007) 27-32 Published online: 28 June 2007 DOI: 10.1051/epjap:2007099