D. Ludovici, F. Gilabert, C.G. Requena, M.E. Gómez, P. López, G.N. Gaydadjiev, J. Duato, Butterfly vs. Unidirectional Fat-Trees for Networks-on-Chip: not a Mere Permutation of Outputs (January 2009), 3rd Workshop on Interconnection Network Architectures: On-Chip, Multi-Chip (INA-OCMC 2009), 25-28 January 2009, Paphos, Cyprus [Conference Paper]