Robuta

https://pure.psu.edu/en/publications/anisotropic-complementary-acoustic-metamaterial-for-canceling-out/ Anisotropic complementary acoustic metamaterial for canceling out aberrating layers - Penn State anisotropic complementary acoustic https://dspace.mit.edu/handle/1721.1/91658 Anisotropic Complementary Acoustic Metamaterial for Canceling out Aberrating Layers anisotropic complementary acoustic canceling layers