Prazen rezhnm na ratsnonachnzztoesknte predloszhsnnia. - Dzhelepov, Simeon T. (Sofnia : Izd-vo na Bulgarskata na naukite, 1968)
Added t.p.: Rechtsregelung der Neuerervoorschlage.
Summary in Russian and German.
Bibliographical footnotes.
Keywords: Inventions -- Bulgaria