Rusinova, Evgeniya, and Georgeta Nazarska. “Digitization of Literary Heritage in the Bulgarian Libraries: Facing Problems and Challenges”. Digital Presentation and Preservation of Cultural and Scientific Heritage 1 (September 30, 2011): 161–164. Accessed April 26, 2024. https://dipp.math.bas.bg/dipp/article/view/dipp.2011.1.17.