Quantum squeezing in coupled waveguide networks with quadratic and qubic nonlinearity R. Julius, A. N. Alias and M. S. A. Halim Eur. Phys. J. Plus, 137 1 (2022) 91 Published online: 07 January 2022 DOI: 10.1140/epjp/s13360-021-02302-1