Akademiku V.A. Obruchevu k pi͡atidesi͡atiletii͡u nauchnoĭ i pedagogicheskoĭ dei͡atelʹnosti

by Obruchev, V. A., Andreĭ Dmitrievich Arkhangelʹskiĭ, E. V. Pavlovskiĭ, S. L. Armazov