%0 Journal Article %T St¨uckelberg particle in external magnetic field. The method of projective operators %A Ovsiyuk, E.M. %A Safronov, A.P. %A Ivashkevich, A.V. %A Semenyuk, O.A. %K St¨uckelberg particle, magnetic field, projective operators, Fedorov– Gronskiy method, exact solutions, bound states %J Proceedings of the Komi Science Centre of the Ural Division of the Russian Academy of Sciences %D 2022 %N 0 %P 9 %I FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"