A cluster of many small holes with negative imaginary surface impedances may generate a negative refraction indexAlsaedi, Ahmed; Ahmad, Bashir; Challa, Durga Prasad; Kirane, Mokhtar; Sini, MouradMathematical methods in the applied sciences2016 / p. 3607-3622 : ill http://dx.doi.org/10.1002/mma.3805

Multiscale analysis of the acoustic scattering by many scatterers of impedance typeChalla, Durga Prasad; Sini, MouradZeitschrift für angewandte Mathematik und Physik2016 / art. 58, p. 1-31 : ill http://dx.doi.org/10.1007/s00033-016-0652-0