Polezni izkopaemi na NR Bŭlgarii͡a︡
Subtitle: vŭglishta i bituminozni shisti.
Publisher: Tekhnika
Published: 1960
Place of publication: Sofia
Language: bul
Number of pages: 168
Subjects: Coal -- Bulgaria; Oil-shales -- Bulgaria
Notes: Bibliography: p. 147-148.
At head of title: Ĭovcho Sm. Ĭovchev.
Summaries in Russian and English.