Ĭordan Stefanov

• Archaeological monuments and history of the research work in the Isperih region
• Arkheologicheski pametnit͡s︡i i istorii͡a︡ na prouchvanii͡a︡ta v Isperikhskii͡a︡ raĭon
• Vladimir Drumev
• Zagadkite na istoriko-arkheologicheskii︠a︡ rezervat Sbori︠a︡novo i Stomogilieto