Li︠u︡dmil Spasov

• 50 years of college and higher education in the Eastern Rhodopes
• Bŭlgarii︠a︡ i SSSR 1917-1944 g
• Bŭlgarii︠a︡ vŭv fotografii i gravi︠u︡ri
• Bŭlgarii︠a︡, velikite sili i balkanskite dŭrzhavi, 1933-1939 g
• Bŭlgaro-sŭvetski diplomaticheski otnoshenii︠a︡ 1934-1944
• Bŭlgarskii︠a︡t XIX i XX vek vŭv fotografii i gravi︠u︡ri
• Konstantin M. Petkovič