A novel mathematical model of smoking: an integer and piece-wise fractional approach Tariq Hassan, Javed Khan, Sayed Saifullah and Gul Zaman Eur. Phys. J. Plus, 137 11 (2022) 1219 Published online: 04 November 2022 DOI: 10.1140/epjp/s13360-022-03413-z