https://catalogue-scientifique.canada.ca/record=1002593~S6*frc
Rechercher Union of Physicists of Bulgaria; Rechercher American Institute of Physics; Rechercher Bŭlgarska akademi︠i︡a na naukite; Rechercher University of Sofia St. Kliment Ohridski
Izd-vo na Bŭlgarskata akademi︠i︡a na naukite, ISSN : 1310-0157
Périodique (revue)