Title: I︠U︡bileen geologicheski sbornik.
Authors: Spasov, Khr,; Spasov, Khristo,; T͡Sankov, Vasil,; Bogdanov, Bogdan D.,; T͡Sankov, Vasil,; Bogdanov, Bogdan D.,; Geologicheski institut (Bŭlgarska akademii͡a na naukite)
Publisher: Izd-vo na Bŭlgarskata akademii︠a︡ na naukite,
Year: 1968
Subjects: Geology Balkan Peninsula.