Method of deriving Lagrangian for two-dimensional systems V. K. Chandrasekar, R. Gladwin Pradeep, R. Mohanasubha, M. Senthilvelan and M. Lakshmanan Eur. Phys. J. Plus, 138 1 (2023) 52 Published online: 20 January 2023 DOI: 10.1140/epjp/s13360-023-03695-x