Oliva, R., J. Ibáñez, R. Cuscó, A. Dadgar, A. Krost, J. Gandhi, A. Bensaoula, and L. Artús (2014a), High-pressure Raman scattering in InGaN heteroepitaxial layers: Effect of the substrate on the phonon pressure coefficients, Applied Physics Letters, 104(14), doi: 10.1063/1.4870529.