Angelova, Gabriela. “The Bulgarian Catholic Book in the System of the Bulgarian Publishing (1878–1944). Geographic Information Systems As a Tool in Presenting and Preserving Literary Cultural Heritage”. Digital Presentation and Preservation of Cultural and Scientific Heritage 14 (September 5, 2024): 259–264. Accessed November 1, 2024. https://dipp.math.bas.bg/dipp/article/view/dipp.2024.14.24.