On the stability of stationary solutions in diffusion models of oncological processes A. Debbouche, M. V. Polovinkina, I. P. Polovinkin, C. A. Valentim Jr. and S. A. David Eur. Phys. J. Plus, 136 1 (2021) 131 Published online: 24 January 2021 DOI: 10.1140/epjp/s13360-020-01070-8