“Purcell effect in Hyperbolic Metamaterial Resonators” A. P. Slobozhanyuk, P. Ginzburg, D. A. Powell, I. Iorsh, A. S. Shalin, P. Segovia, A. V. Krasavin, G. A. Wurtz, V.A. Podolskiy, P. A. Belov and A. V. Zayats, Phys. Rev. B. 92, 195127 (2015). https://doi.org/10.1103/PhysRevB.92.195127