Rumen Ivanov

• Biznes ent͡s︡iklopedii͡a︡
• Bŭlgarskata narodnost XIX-XXI vek
• Nevidimite bŭlgari v I︠U︡zhna Makedonii︠a︡
• Roman cities in Bulgaria
• Thracia
• Vsekidnevnii︠a︡t zhivot v Trakii︠a︡ prez I-IV v.
• Zabravenite nashi sŭnarodnit︠s︡i v Egeĭska Makedonii︠a︡