Propagation of H1N1 virus through saliva movement in oesophagus: a mathematical model Daya Ram, D. S. Bhandari, Dharmendra Tripathi and Kushal Sharma Eur. Phys. J. Plus, 137 7 (2022) 866 Published online: 27 July 2022 DOI: 10.1140/epjp/s13360-022-03070-2