Kupriyanov V. G. Symplectic realization of electric charge in fields of monopole distributions / V. G. Kupriyanov, R. J. Szabo // Physical Review D. 2018. Vol. 98, № 4. P. 045005-1-045005-25. URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000634981