Great Soviet encyclopedia,Vol.23
Prokhorov,A M.
Great Soviet encyclopedia,Vol.23 - 3rd ed. - Newyork Macmillan 1979 - 746p.
037 / PRO/G.23
Great Soviet encyclopedia,Vol.23 - 3rd ed. - Newyork Macmillan 1979 - 746p.
037 / PRO/G.23