@article{JNSA_2025_18_1_a0,
     author = {Tzenov, Stephan I.},
     title = {The method of formal series: applications to nonlinear beam dynamics and invariants of motion },
     journal = {Journal of nonlinear sciences and its applications},
     pages = {1-19},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {2025},
     doi = {10.22436/jnsa.018.01.01},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.22436/jnsa.018.01.01/}
}