Catalogue of the Earthquakes in the Territory of Bulgaria for the Period 1900-1977 Вид публикации: Book Авторы: E. Grigorova; D. Sokerova; Ludmil Christoskov; Sn. Rizhikova Источник: Sofia: Bulgarian Acad¬emy of Sciences, Archives of the Geophysical Institute of BAS, 1979 (1979)
