(2) W. E. Kock:“Metallic Delay Lenses,” Bell System Tech. J., Vol. 27, 58-83 (1948)
(3) J. Brown:“Artificial dielectrics”, Progress in dielectrics, Vol. 2, pp. 195-225 (1960)
(4) W. Rotman:“Plasma simulation by artificial and parallel plate media,” IRE Trans. Ant. Propagat., Vol. 10, pp. 82-95 (1962)
(5) V. G. Veselago:“The electrodynamics of substances with simultaneously negative values of e and μ,” Soviet Physics Uspekhi, Vol. 10, No. 4, pp. 509-514 (1968)