Extreme and critical transition events in the memristor based Liénard system S. Leo Kingston, K. Suresh, K. Thamilmaran and T. Kapitaniak Eur. Phys. J. Special Topics, 229 6-7 (2020) 1033-1044 Published online: 26 March 2020 DOI: 10.1140/epjst/e2020-900165-1