2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/87585Some first principles that, we believe, could serve as foundation for quantum theory of extended particles are formulated. It is also shown that in the point-like particles limit the non-relativistic quantum mechanics can be restored. As an illustration the soliton model of hydrogen atom is considered.RevTex, 4 pages, to be published in the proc. PFQT98, DubnaAtomic Physicstext